Kemandi Q&A - Got homework? We can help. - Recent questions and answers in Physics
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Powered by Question2AnswerRichard is riding the giant drop at the 4 carnival if Richard free fall falls for 2.6 seconds what will be the final velocity and how far will be he fall
http://www.kemandi.com/3623/richard-riding-carnival-richard-falls-seconds-final-velocity
Physicshttp://www.kemandi.com/3623/richard-riding-carnival-richard-falls-seconds-final-velocitySat, 29 Jul 2017 13:22:00 +0000A kangaroo is capable of jumping to a height of 2.62 m . Determine the takeoff speed of the kangaroo
http://www.kemandi.com/3435/kangaroo-capable-jumping-height-determine-takeoff-kangaroo
Physicshttp://www.kemandi.com/3435/kangaroo-capable-jumping-height-determine-takeoff-kangarooWed, 31 May 2017 05:50:52 +00004.A stone is dropped into a deep well and is heard to hit the water 3.41 s after being dropped. Determine the depth of the well.
http://www.kemandi.com/3434/stone-dropped-heard-water-after-being-dropped-determine-depth
Physicshttp://www.kemandi.com/3434/stone-dropped-heard-water-after-being-dropped-determine-depthTue, 30 May 2017 14:39:58 +0000A coin id dropped into a deep well and is heart to hit the water 3.41s after dropped determine the depth of the well
http://www.kemandi.com/3433/dropped-well-heart-water-after-dropped-determine-depth-well
Physicshttp://www.kemandi.com/3433/dropped-well-heart-water-after-dropped-determine-depth-wellMon, 29 May 2017 02:02:49 +0000Answered: A stone is dropped into a deep well and is heard to hit the water 3.41 s after being dropped. Determine the depth of the well.
http://www.kemandi.com/357/stone-dropped-heard-water-after-being-dropped-determine-depth?show=3432#a3432
h=ut+1/2gt^2 here,t=3.41s; u=0 ;g=9.8 m/s^2;h=?<br />
<br />
=0+1/2*9.8*(3.41)^2 <br />
=56.98 m<br />
<br />
=57 mPhysicshttp://www.kemandi.com/357/stone-dropped-heard-water-after-being-dropped-determine-depth?show=3432#a3432Fri, 26 May 2017 14:24:25 +0000Answered: Find the position on the x-axis where the net force on a small charge +q would be zero.
http://www.kemandi.com/7/find-the-position-axis-where-net-force-small-charge-would-zero?show=3397#a3397
gjhgjgjhgjhgjjhgjhPhysicshttp://www.kemandi.com/7/find-the-position-axis-where-net-force-small-charge-would-zero?show=3397#a3397Thu, 26 Jan 2017 21:26:58 +0000hello i have just one question why there is 0.5?
http://www.kemandi.com/3382/hello-i-have-just-one-question-why-there-is-0-5
Physicshttp://www.kemandi.com/3382/hello-i-have-just-one-question-why-there-is-0-5Thu, 08 Dec 2016 11:35:51 +0000If a splash of sound is heard 4. 23 s after a stone is dropped into a well 78. 4 m deep the velocity of the sound in air?
http://www.kemandi.com/3381/splash-sound-heard-after-stone-dropped-deep-velocity-sound
Physicshttp://www.kemandi.com/3381/splash-sound-heard-after-stone-dropped-deep-velocity-soundWed, 07 Dec 2016 16:18:15 +0000Answered: How come in free fall you feel weightless even though gravity is pulling down on you? (ignore air resistance when answering this question).
http://www.kemandi.com/3085/weightless-gravity-pulling-resistance-answering-question?show=3370#a3370
i dont knowPhysicshttp://www.kemandi.com/3085/weightless-gravity-pulling-resistance-answering-question?show=3370#a3370Mon, 31 Oct 2016 13:16:08 +0000Speed of kangaroo
http://www.kemandi.com/3318/speed-of-kangaroo
A kangaroo is capable jumping two a height of 2.62m ditermint the take off speed of the kangarooPhysicshttp://www.kemandi.com/3318/speed-of-kangarooTue, 09 Aug 2016 13:39:09 +0000what is the push force F?
http://www.kemandi.com/3116/what-is-the-push-force-f
<p>A 50 kg crate is being pushed on a horizontal floor at constant velocity. Given that the coefficient of kinetic friction between crate and floor is <img alt="\mu" src="http://latex.codecogs.com/gif.latex?%5Cmu"><em><sub>k</sub></em> = 0.1, what is the push force <em>F</em>?</p>Physicshttp://www.kemandi.com/3116/what-is-the-push-force-fWed, 28 Oct 2015 06:32:41 +0000What is the minimum angle theta so that the ladder doesn't slip?
http://www.kemandi.com/3115/what-is-the-minimum-angle-theta-so-that-the-ladder-doesnt-slip
<p>A uniform ladder of length <em>L</em> is leaning against the side of a building, as shown. A person of mass <em>m</em> = 75 kg is standing on it. The mass of the ladder is <em>M</em> = 10 kg. The coefficient of static friction between the ground and ladder is <img alt="\mu" src="http://latex.codecogs.com/gif.latex?%5Cmu"><em><sub>s1</sub></em> = 0.5, and the coefficient of static friction between the wall and ladder is <img alt="\mu" src="http://latex.codecogs.com/gif.latex?%5Cmu"><em><sub>s2</sub></em> = 0.3. What is the minimum angle <img alt="\theta" src="http://latex.codecogs.com/gif.latex?%5Ctheta"> so that the ladder doesn't slip?
<br> </p>Physicshttp://www.kemandi.com/3115/what-is-the-minimum-angle-theta-so-that-the-ladder-doesnt-slipWed, 28 Oct 2015 06:31:43 +0000Determine the acceleration of the blocks.
http://www.kemandi.com/3114/determine-the-acceleration-of-the-blocks
<p>Two blocks of mass <em>m</em> and <em>M</em> are hanging off a single pulley. Determine the acceleration of the blocks. Ignore the mass of the pulley.</p>Physicshttp://www.kemandi.com/3114/determine-the-acceleration-of-the-blocksWed, 28 Oct 2015 06:28:46 +0000The spring has a stiffness k. How much is the spring compressed?
http://www.kemandi.com/3113/the-spring-has-stiffness-k-how-much-is-the-spring-compressed
<p>A block of mass <em>M</em> falls onto a spring. Before colliding with the spring the velocity of the block is <em>V</em>. The spring has a stiffness <em>k</em>. How much is the spring compressed?</p>Physicshttp://www.kemandi.com/3113/the-spring-has-stiffness-k-how-much-is-the-spring-compressedWed, 28 Oct 2015 06:27:40 +0000How much is the spring compressed?
http://www.kemandi.com/3112/how-much-is-the-spring-compressed
<p>A block of mass <em>M</em> is traveling on a surface inclined at angle <img alt="\theta" src="http://latex.codecogs.com/gif.latex?%5Ctheta">. The coefficient of kinetic friction is <img alt="\mu" src="http://latex.codecogs.com/gif.latex?%5Cmu"> between block and surface. The velocity of the block is <em>V</em> before colliding with a spring. The spring has a stiffness <em>k</em>. How much is the spring compressed?</p>Physicshttp://www.kemandi.com/3112/how-much-is-the-spring-compressedWed, 28 Oct 2015 06:26:18 +0000Using an energy analysis determine which person is correct.
http://www.kemandi.com/3111/using-an-energy-analysis-determine-which-person-is-correct
Two people are at the gym having a debate about how much energy is required to bench press a certain weight for one repetition. One person says that the energy required depends on how fast the weight is lifted. The other person says that it doesn't matter. Using an energy analysis determine which person is correct.Physicshttp://www.kemandi.com/3111/using-an-energy-analysis-determine-which-person-is-correctWed, 28 Oct 2015 06:22:48 +0000Answered: What is its wavelength?
http://www.kemandi.com/3095/what-is-its-wavelength?show=3101#a3101
Velocity = wavelength x frequency.<br />
<br />
Because all units are in standard SI<br />
<br />
350 = wavelength x 500<br />
<br />
wavelength = .7 mPhysicshttp://www.kemandi.com/3095/what-is-its-wavelength?show=3101#a3101Sat, 17 Oct 2015 15:11:47 +0000What will be the force between two wires?
http://www.kemandi.com/3097/what-will-be-the-force-between-two-wires
<p>Two long straight wires carrying the same current <strong><em> I </em></strong> and separated by a distance <strong><em>r </em></strong>exert a force <strong><em>F </em></strong> on each other. The current is increased to <strong><em>4I </em></strong>and the separation is reduced to <strong><em>r/6 </em></strong>.</p>Physicshttp://www.kemandi.com/3097/what-will-be-the-force-between-two-wiresMon, 12 Oct 2015 21:42:10 +0000How far away in meters is the next pressure maximum?
http://www.kemandi.com/3096/how-far-away-in-meters-is-the-next-pressure-maximum
A saxophone is playing a steady note of frequency 266 Hz. The temperature in the room is 25 C. Suppose that at some instant the varying pressure at your eardrum is at a maximum.Physicshttp://www.kemandi.com/3096/how-far-away-in-meters-is-the-next-pressure-maximumMon, 12 Oct 2015 21:41:02 +0000What is the velocity of the arrow immediately after release?
http://www.kemandi.com/3086/what-is-the-velocity-of-the-arrow-immediately-after-release
An archer pulls back 0.75 m on a bow which has a stiffness of 200 N/m. The arrow weighs 50 g.Physicshttp://www.kemandi.com/3086/what-is-the-velocity-of-the-arrow-immediately-after-releaseThu, 01 Oct 2015 03:43:26 +0000From these equations derive the equation for centripetal acceleration.
http://www.kemandi.com/3084/these-equations-derive-equation-centripetal-acceleration
<p>A particle is moving around in a circle and its position is given in polar coordinates as</p>
<p>x = Rcos(theta)</p>
<p>y = Rsin(theta)</p>
<p>, where <em>R </em>is the radius of the circle, and theta is in radians.</p>Physicshttp://www.kemandi.com/3084/these-equations-derive-equation-centripetal-accelerationThu, 01 Oct 2015 03:42:35 +0000Answered: What is the speed of a 20g bullet?
http://www.kemandi.com/3035/what-is-the-speed-of-a-20g-bullet?show=3039#a3039
<p>Conservation of momentum leads to .02 v - 5.02 V.</p>
<p><img alt="5.02 V^2 = f (1.5)" src="http://latex.codecogs.com/gif.latex?5.02%20V%5E2%20%3D%20f%20%281.5%29"></p>
<p>where f = .7 N (since net force is 0 for a constant velocity object). Find V, then determine from the first expression that v = 162 m/s.</p>Physicshttp://www.kemandi.com/3035/what-is-the-speed-of-a-20g-bullet?show=3039#a3039Sun, 20 Sep 2015 15:45:32 +0000Answered: What is the momentum of the ball as it leaves the floor?
http://www.kemandi.com/3036/what-is-the-momentum-of-the-ball-as-it-leaves-the-floor?show=3038#a3038
<p><img alt="e = \frac{v_2}{v_1}" src="http://latex.codecogs.com/gif.latex?e%20%3D%20%5Cfrac%7Bv_2%7D%7Bv_1%7D"> where e is coefficient of restitution</p>
<p>.8 = v_2 / 5</p>
<p>v_2 = 4 ft/sec</p>Physicshttp://www.kemandi.com/3036/what-is-the-momentum-of-the-ball-as-it-leaves-the-floor?show=3038#a3038Sun, 20 Sep 2015 15:44:13 +0000Answered: What constant force is needed to stop the rock in 7*10-4 sec?
http://www.kemandi.com/3034/what-constant-force-is-needed-to-stop-the-rock-in-7-10-4-sec?show=3037#a3037
Impulse on rock = change in momentum of rock:<br />
<br />
Ft = mv_final - mv_initial<br />
<br />
F(7*10^-4) = 0 - (2)(6m/s)<br />
<br />
F = -1.71 * 10^4 N<br />
The minus sign indicates that the force opposes the motionPhysicshttp://www.kemandi.com/3034/what-constant-force-is-needed-to-stop-the-rock-in-7-10-4-sec?show=3037#a3037Sun, 20 Sep 2015 15:42:41 +0000Answered: How fast must you be traveling if you detect a frequency of 429 Hz?
http://www.kemandi.com/2435/how-fast-must-you-traveling-if-you-detect-frequency-of-429-hz?show=2439#a2439
f' = f(c - v)/c<br />
<br />
pitch heard by listener: f' = 490 Hz<br />
<br />
pitch of stationary source: f = 520 Hz<br />
<br />
speed of sound in air: c = 330 m/s<br />
<br />
So, v = c - (f'/f)c = 330 - (490/520)330 = 330(1 - 490/520) = 330*0.0577 = 19 m/sPhysicshttp://www.kemandi.com/2435/how-fast-must-you-traveling-if-you-detect-frequency-of-429-hz?show=2439#a2439Sat, 19 Sep 2015 17:53:51 +0000Answered: If the stationaly female hears a tone of 1240 Hz, what is the speed of sound in the atmosphere of Arrakis?
http://www.kemandi.com/2434/stationaly-female-hears-1240-speed-sound-atmosphere-arrakis?show=2438#a2438
1240-1200 = 40 Hz<br />
<br />
v = Wavelength*Frequency<br />
Wavelength = 25/40 = 0.625m<br />
<br />
The velocity of sound is:<br />
v = 0.625*1200 (not 1240, because the sound would not be travelling that 25m/s faster)<br />
v = 750 m/sPhysicshttp://www.kemandi.com/2434/stationaly-female-hears-1240-speed-sound-atmosphere-arrakis?show=2438#a2438Sat, 19 Sep 2015 17:47:23 +0000Answered: Does pitch or frequency of an organ pipe increase or decrease with increasing temperature? Explain.
http://www.kemandi.com/2432/frequency-increase-decrease-increasing-temperature-explain?show=2437#a2437
Higher temperature = faster velocity of molecules, transmitting sound more quickly = higher frequency, so higher pitch.<br />
<br />
Pitch/frequency increases with increasing temperature.Physicshttp://www.kemandi.com/2432/frequency-increase-decrease-increasing-temperature-explain?show=2437#a2437Sat, 19 Sep 2015 17:19:25 +0000Answered: When sound travels from air into water, does the frequency, speed, wavelength of the wave change?
http://www.kemandi.com/2431/sound-travels-water-frequency-speed-wavelength-wave-change?show=2436#a2436
Sound travels faster in a denser medium, so water being denser than air, sound will travel faster in water than air. Speed and wavelength change. Since the increase in wavelength is due to the increase in speed, these are proportional to each other,, so the frequency doesn't change.Physicshttp://www.kemandi.com/2431/sound-travels-water-frequency-speed-wavelength-wave-change?show=2436#a2436Fri, 18 Sep 2015 18:46:31 +0000What is the fundamental frequency if one end is plugged?
http://www.kemandi.com/2433/what-is-the-fundamental-frequency-if-one-end-is-plugged
The fundamental frequency of an open pipe is 594 Hz.Physicshttp://www.kemandi.com/2433/what-is-the-fundamental-frequency-if-one-end-is-pluggedFri, 18 Sep 2015 18:35:05 +0000Answered: What is the potential energy of the spring when a 60.0 kg mass hangs vertically from it?
http://www.kemandi.com/2423/what-potential-energy-spring-when-mass-hangs-vertically-from?show=2430#a2430
F = kx<br />
k = F/x = 720/0.15 = 4800 N/m<br />
<br />
F = mg = kx<br />
x = mg/k = 60 x 9.81/4800 = 0.122 mPhysicshttp://www.kemandi.com/2423/what-potential-energy-spring-when-mass-hangs-vertically-from?show=2430#a2430Fri, 18 Sep 2015 18:19:03 +0000Answered: What horizontal force is necessary to hold the bag in a position displaced sideways 3 m from its initial position?
http://www.kemandi.com/2422/horizontal-necessary-position-displaced-sideways-position?show=2429#a2429
Draw a triangle. The hypoteneuse of the triangle is the length of the rope and is 6.0m. The opposite side from the angle formed by the rope and the vertical is 3.0. From this, you can figure out the angle from vertical to be 30 degrees.<br />
<br />
F = 120kg * sin(30) = 120 * .5 = 60 NPhysicshttp://www.kemandi.com/2422/horizontal-necessary-position-displaced-sideways-position?show=2429#a2429Fri, 18 Sep 2015 18:18:12 +0000Answered: What is the speed of the crate when it is 2m from its initial position?
http://www.kemandi.com/2424/what-is-the-speed-the-crate-when-2m-from-its-initial-position?show=2428#a2428
W = F*D, where W is work, F is force, D is distance<br />
<br />
F = W/D = 360/5.60 = 64.3 N<br />
Work done by this force after the crate moves 2 m = 64.3(2) = 129 J<br />
The KE after the crate moves 2 m = 360 J - 129 J = 231 J<br />
KE = 1/2mV² = 231 J<br />
V² = 231(2)/50 = 9.24<br />
V = 3.04 m/sPhysicshttp://www.kemandi.com/2424/what-is-the-speed-the-crate-when-2m-from-its-initial-position?show=2428#a2428Fri, 18 Sep 2015 18:12:20 +0000Answered: Explain how she increases the total Mechanical energy.
http://www.kemandi.com/2420/explain-how-she-increases-the-total-mechanical-energy?show=2427#a2427
She transfers some muscular energy from her body to depress the trampoline(spring) a little further each time to rebound higher, thus acquiring more PE for the next descent.Physicshttp://www.kemandi.com/2420/explain-how-she-increases-the-total-mechanical-energy?show=2427#a2427Fri, 18 Sep 2015 05:12:24 +0000Answered: What becomes of its potential energy?
http://www.kemandi.com/2421/what-becomes-of-its-potential-energy?show=2426#a2426
I think PE turns into KE (equal to the PE) meaning that as the spring dissolved, eventually it would lose its structural integrity and the pieces of the spring would fly apart. The pieces would then be stopped by friction in the acid.Physicshttp://www.kemandi.com/2421/what-becomes-of-its-potential-energy?show=2426#a2426Wed, 16 Sep 2015 17:36:43 +0000Answered: Is it possible for a frictional force to increase the mechanical energy of a system? If so, give examples.
http://www.kemandi.com/2419/possible-frictional-increase-mechanical-energy-examples?show=2425#a2425
Yes. When you start walking (accelerate) forwards, it is the static frictional force of the ground on your foot that accelerates you - increasing your mechanical (kinetic in this case) energy.<br />
Same with ropes, gears, pulleys, etc.Physicshttp://www.kemandi.com/2419/possible-frictional-increase-mechanical-energy-examples?show=2425#a2425Wed, 16 Sep 2015 17:34:48 +0000Answered: At what distance from the wire is the electric field magnitude equal to 2.46N/C ?
http://www.kemandi.com/6/what-distance-from-wire-electric-field-magnitude-equal-46n?show=2415#a2415
Using Gauss's Theorem we can get the electric field due to a long straight charged wire:<br />
<br />
E = λ/(2πrε) where λ = 1.41 x 10^(-10) C/m<br />
1/(4πε) = K = 9 x 10^9<br />
So,<br />
E = 2Kλ/r<br />
r = 2Kλ/E = 2 x 9 x 10^9 x 1.41 x 10^(-10)/2.46 = 1.03 mPhysicshttp://www.kemandi.com/6/what-distance-from-wire-electric-field-magnitude-equal-46n?show=2415#a2415Mon, 14 Sep 2015 19:50:01 +0000Locate the point where electric field due to the two charges is zero.
http://www.kemandi.com/1993/locate-the-point-where-electric-field-due-the-two-charges-zero
Two point charges, q1 = -5q, and q2 = +2q, are separated by distance d. Locate the point where electric field due to the two charges is zero.Physicshttp://www.kemandi.com/1993/locate-the-point-where-electric-field-due-the-two-charges-zeroTue, 08 Sep 2015 16:57:03 +0000Answered: How far beyond the traffic light will the automobile overtake the truck?
http://www.kemandi.com/1829/far-beyond-traffic-light-will-automobile-overtake-the-truck?show=1895#a1895
<p>Truck: <img alt="x_t = 9.6 t" src="http://latex.codecogs.com/gif.latex?x_t%20%3D%209.6%20t"></p>
<p>Automobile: <img alt="x_a = x_I+v_ot + (1/2)at^2 - 0+0t + (1/2)2.2t^2 = 1.1t^2" src="http://latex.codecogs.com/gif.latex?x_a%20%3D%20x_I&plus;v_ot%20&plus;%20%281/2%29at%5E2%20-%200&plus;0t%20&plus;%20%281/2%292.2t%5E2%20%3D%201.1t%5E2"></p>
<p>Then, since they get to the same location, set them equal:</p>
<p><img alt="9.5 t = 1.1t^2" src="http://latex.codecogs.com/gif.latex?9.5%20t%20%3D%201.1t%5E2"></p>
<p><img alt="t=9.5/1.1 =8.6 sec" src="http://latex.codecogs.com/gif.latex?t%3D9.5/1.1%20%3D8.6%20sec"></p>
<p>Substitute back in equation for the automobile to get its location:</p>
<p><img alt="x=(1.1)8.6^2 = 82 meters" src="http://latex.codecogs.com/gif.latex?x%3D%281.1%298.6%5E2%20%3D%2082%20meters"></p>Physicshttp://www.kemandi.com/1829/far-beyond-traffic-light-will-automobile-overtake-the-truck?show=1895#a1895Mon, 07 Sep 2015 23:36:35 +0000Answered: With what speed must a ball be thrown vertically up in order to rise to a max height of 50m?
http://www.kemandi.com/1830/with-what-speed-must-ball-thrown-vertically-order-rise-height?show=1894#a1894
<p><img alt="v^2 = v_0^2 -2g(y-y_0) = 0" src="http://latex.codecogs.com/gif.latex?v%5E2%20%3D%20v_0%5E2%20-2g%28y-y_0%29%20%3D%200"></p>
<p><img alt="v_0^2 = 2g(y-y_0)" src="http://latex.codecogs.com/gif.latex?v_0%5E2%20%3D%202g%28y-y_0%29"></p>
<p><img alt="v = \sqrt {2(9.8)(50)} = 31" src="http://latex.codecogs.com/gif.latex?v%20%3D%20%5Csqrt%20%7B2%289.8%29%2850%29%7D%20%3D%2031"> m/s</p>Physicshttp://www.kemandi.com/1830/with-what-speed-must-ball-thrown-vertically-order-rise-height?show=1894#a1894Mon, 07 Sep 2015 23:30:16 +0000Answered: How long does i take the stone to reach the ground? What is the speed of the stone at impact?
http://www.kemandi.com/1831/long-does-take-stone-reach-ground-what-speed-the-stone-impact?show=1893#a1893
<p>Speed of stone at impact:</p>
<p><img alt="v^2 =v_0^2 -2g(y-y_0)" src="http://latex.codecogs.com/gif.latex?v%5E2%20%3Dv_0%5E2%20-2g%28y-y_0%29"></p>
<p><img alt="v = \pm \sqrt{ (-12^2 - 2(9.81)(0-30))} = \pm 27 m/s" src="http://latex.codecogs.com/gif.latex?v%20%3D%20%5Cpm%20%5Csqrt%7B%20%28-12%5E2%20-%202%289.81%29%280-30%29%29%7D%20%3D%20%5Cpm%2027%20m/s"></p>
<p>Then, time of flight can be found:</p>
<p><img alt="v = v_o-gt" src="http://latex.codecogs.com/gif.latex?v%20%3D%20v_o-gt"></p>
<p><img alt="t = \frac{v_0-v}{g} = (-12 -(-27)) / 9.81= 1.53 seconds" src="http://latex.codecogs.com/gif.latex?t%20%3D%20%5Cfrac%7Bv_0-v%7D%7Bg%7D%20%3D%20%28-12%20-%28-27%29%29%20/%209.81%3D%201.53%20seconds"></p>Physicshttp://www.kemandi.com/1831/long-does-take-stone-reach-ground-what-speed-the-stone-impact?show=1893#a1893Mon, 07 Sep 2015 23:28:46 +0000Answered: How far does the muon take to stop?
http://www.kemandi.com/1828/how-far-does-the-muon-take-to-stop?show=1892#a1892
<p><img alt="v^2 = v_o^2 + 2a(x-x_0)" src="http://latex.codecogs.com/gif.latex?v%5E2%20%3D%20v_o%5E2%20&plus;%202a%28x-x_0%29"></p>
<p>Solve for x:</p>
<p><img alt="x = \frac{v^2 - v_0^2}{ 2a} + x_0 = \frac{0 - (5e6)^2}{ 2(-1.25e14)} = .1 m" src="http://latex.codecogs.com/gif.latex?x%20%3D%20%5Cfrac%7Bv%5E2%20-%20v_0%5E2%7D%7B%202a%7D%20&plus;%20x_0%20%3D%20%5Cfrac%7B0%20-%20%285e6%29%5E2%7D%7B%202%28-1.25e14%29%7D%20%3D%20.1%20m"></p>Physicshttp://www.kemandi.com/1828/how-far-does-the-muon-take-to-stop?show=1892#a1892Mon, 07 Sep 2015 23:25:49 +0000Answered: What is the maximum altitude reached?
http://www.kemandi.com/1832/what-is-the-maximum-altitude-reached?show=1842#a1842
<p>Altitude when fuel fails:</p>
<p><img alt="y_{f} = y_o + v_o * t + \frac{1}{2}at^2 = 0+0 + (.5)(4)(6^2) = 72 m" src="http://latex.codecogs.com/gif.latex?y_%7Bf%7D%20%3D%20y_o%20&plus;%20v_o%20*%20t%20&plus;%20%5Cfrac%7B1%7D%7B2%7Dat%5E2%20%3D%200&plus;0%20&plus;%20%28.5%29%284%29%286%5E2%29%20%3D%2072%20m"></p>
<p>Speed at moment fuel fails:</p>
<p><img alt="v_f = v_o + at = 0 + 4(6)=24m/s" src="http://latex.codecogs.com/gif.latex?v_f%20%3D%20v_o%20&plus;%20at%20%3D%200%20&plus;%204%286%29%3D24m/s"></p>
<p>Without fuel:</p>
<p><img alt="v^2 = v_0 ^2 -2g(y2-y1)" src="http://latex.codecogs.com/gif.latex?v%5E2%20%3D%20v_0%20%5E2%20-2g%28y2-y1%29"></p>
<p><img alt="y = y_o + (\frac{v_o^2 - v_f^2}{2g}) = 72 + (24^2)/ (2*9.8) = 101 meters" src="http://latex.codecogs.com/gif.latex?y%20%3D%20y_o%20&plus;%20%28%5Cfrac%7Bv_o%5E2%20-%20v_f%5E2%7D%7B2g%7D%29%20%3D%2072%20&plus;%20%2824%5E2%29/%20%282*9.8%29%20%3D%20101%20meters"></p>Physicshttp://www.kemandi.com/1832/what-is-the-maximum-altitude-reached?show=1842#a1842Sun, 06 Sep 2015 18:42:26 +0000Answered: How high above the target must the rifle barrel be pointed so that the bullet hits dead center?
http://www.kemandi.com/1833/above-target-must-rifle-barrel-pointed-that-bullet-dead-center?show=1840#a1840
<p>If the target is at the same height above the ground as the rifle, you can use the range equation:<img alt="R = \frac{v_o ^2}{g} sin{2\alpha}" src="http://latex.codecogs.com/gif.latex?R%20%3D%20%5Cfrac%7Bv_o%20%5E2%7D%7Bg%7D%20sin%7B2%5Calpha%7D"></p>
<p>Solve for <img alt="2\alpha: sin^{-1}( {\frac{Rg}{v^2})" src="http://latex.codecogs.com/gif.latex?2%5Calpha%3A%20sin%5E%7B-1%7D%28%20%7B%5Cfrac%7BRg%7D%7Bv%5E2%7D%29"> = .12<sup>o</sup></p>
<p>Thus, <img alt="\alpha = (.5)(.12) = .06^o" src="http://latex.codecogs.com/gif.latex?%5Calpha%20%3D%20%28.5%29%28.12%29%20%3D%20.06%5Eo"></p>
<p><img alt="h = (150 feet)(tan(.06)) = 1.9 inches" src="http://latex.codecogs.com/gif.latex?h%20%3D%20%28150%20feet%29%28tan%28.06%29%29%20%3D%201.9%20inches"></p>
<p> </p>
<p> </p>Physicshttp://www.kemandi.com/1833/above-target-must-rifle-barrel-pointed-that-bullet-dead-center?show=1840#a1840Sun, 06 Sep 2015 17:49:51 +0000Answered: What is the speed of the plane? How far did the projectile travel horizontally during its flight?
http://www.kemandi.com/1834/speed-plane-projectile-travel-horizontally-during-flight?show=1839#a1839
<p><img alt="y=y_o + v_{0y}t - \frac{1}{2}gt^2" src="http://latex.codecogs.com/gif.latex?y%3Dy_o%20&plus;%20v_%7B0y%7Dt%20-%20%5Cfrac%7B1%7D%7B2%7Dgt%5E2"></p>
<p><img alt="v_{oy}=v_o * sin\theta = \frac{y-y_o + \frac{1}{2}gt^2}{t}" src="http://latex.codecogs.com/gif.latex?v_%7Boy%7D%3Dv_o%20*%20sin%5Ctheta%20%3D%20%5Cfrac%7By-y_o%20&plus;%20%5Cfrac%7B1%7D%7B2%7Dgt%5E2%7D%7Bt%7D"></p>
<p><img alt="v_o = \frac{y-y_o + \frac{1}{2}gt^2}{sin\theta*t}} = \frac{0-630+(.5)(9.8)(5^2)}{sin(-37)*5)} = 202 m/s" src="http://latex.codecogs.com/gif.latex?v_o%20%3D%20%5Cfrac%7By-y_o%20&plus;%20%5Cfrac%7B1%7D%7B2%7Dgt%5E2%7D%7Bsin%5Ctheta*t%7D%7D%20%3D%20%5Cfrac%7B0-630&plus;%28.5%29%289.8%29%285%5E2%29%7D%7Bsin%28-37%29*5%29%7D%20%3D%20202%20m/s"></p>
<p>The horizontal distance:</p>
<p><img alt="v_x = v_{ox} = v_o * cos \theta = 202*cos(-37) = 161 m/s" src="http://latex.codecogs.com/gif.latex?v_x%20%3D%20v_%7Box%7D%20%3D%20v_o%20*%20cos%20%5Ctheta%20%3D%20202*cos%28-37%29%20%3D%20161%20m/s"></p>
<p><img alt="\Delta x = v_x * t = 161*5 seconds = 806" src="http://latex.codecogs.com/gif.latex?%5CDelta%20x%20%3D%20v_x%20*%20t%20%3D%20161*5%20seconds%20%3D%20806"> meters</p>Physicshttp://www.kemandi.com/1834/speed-plane-projectile-travel-horizontally-during-flight?show=1839#a1839Sun, 06 Sep 2015 17:36:59 +0000Answered: Shat is the speed of a particle on the star's equator and its centripetal acceleration?
http://www.kemandi.com/1835/shat-speed-particle-stars-equator-centripetal-acceleration?show=1838#a1838
<p>Circumference = <img alt="2\pi r" src="http://latex.codecogs.com/gif.latex?2%5Cpi%20r"></p>
<p><img alt="v = C/T = \frac{2\pi r}{T} = \frac{2 \pi (2e4)}{1 second} = 1.3*10^5 m/s" src="http://latex.codecogs.com/gif.latex?v%20%3D%20C/T%20%3D%20%5Cfrac%7B2%5Cpi%20r%7D%7BT%7D%20%3D%20%5Cfrac%7B2%20%5Cpi%20%282e4%29%7D%7B1%20second%7D%20%3D%201.3*10%5E5%20m/s"></p>
<p>Centripetal acceleration = a = <img alt="v^2/R = 7.9*10^5 m/s^2" src="http://latex.codecogs.com/gif.latex?v%5E2/R%20%3D%207.9*10%5E5%20m/s%5E2"></p>Physicshttp://www.kemandi.com/1835/shat-speed-particle-stars-equator-centripetal-acceleration?show=1838#a1838Sun, 06 Sep 2015 17:29:06 +0000Answered: At what angle from the vertical do the snowflakes appear to be falling as viewed by the driver of a car traveling on a straight road with a speed of 50 km/h?
http://www.kemandi.com/1836/vertical-snowflakes-falling-viewed-driver-traveling-straight?show=1837#a1837
<p>Let v_sc = velocity of snow relative to car</p>
<p>Let v_cg = velocity of car relative to ground (v_cg = 50 km/h = 13.9 m/s)</p>
<p>v_sg = v_sc + v_cg = velocity of snow relative to ground (v_sg = 8 m/s)</p>
<p>Draw a vector diagram to help, and you get:</p>
<p><img alt="tan\theta = \frac{v_{cg}}{v_{sg}}" src="http://latex.codecogs.com/gif.latex?tan%5Ctheta%20%3D%20%5Cfrac%7Bv_%7Bcg%7D%7D%7Bv_%7Bsg%7D%7D"></p>
<p><img alt="\theta = tan^{-1}(\frac{13.9}{8}) = 60^o" src="http://latex.codecogs.com/gif.latex?%5Ctheta%20%3D%20tan%5E%7B-1%7D%28%5Cfrac%7B13.9%7D%7B8%7D%29%20%3D%2060%5Eo"></p>Physicshttp://www.kemandi.com/1836/vertical-snowflakes-falling-viewed-driver-traveling-straight?show=1837#a1837Sun, 06 Sep 2015 16:28:35 +0000Answered: What is the order in which they arrive at the bottom of the incline?
http://www.kemandi.com/1733/what-is-the-order-which-they-arrive-at-the-bottom-the-incline?show=1825#a1825
Solid sphere, solid cylinder, spherical shell, then hoop.<br />
<br />
The more mass is closer to the center of the object (where the center of mass is in these cases), the faster it will roll.<br />
<br />
You can also calculate the moment of inertias for each object. The greater the moment of inertia, the faster it will arrive at the bottom.<br />
<br />
hoop: I= MR²<br />
solid cylinder: I= (1/2)MR²<br />
solid sphere: I= (2/5)MR²<br />
spherical shell: I= (2/3)MR²Physicshttp://www.kemandi.com/1733/what-is-the-order-which-they-arrive-at-the-bottom-the-incline?show=1825#a1825Fri, 04 Sep 2015 15:22:32 +0000Answered: Does magnitude of the electric field due to the charge increase, decrease, or remain the same at points...
http://www.kemandi.com/1800/magnitude-electric-charge-increase-decrease-remain-points?show=1816#a1816
<p>a) Same: E = 0</p>
<p>b) Decreases: <img alt="E = \frac{kQ}{R^2}" src="http://latex.codecogs.com/gif.latex?E%20%3D%20%5Cfrac%7BkQ%7D%7BR%5E2%7D"></p>Physicshttp://www.kemandi.com/1800/magnitude-electric-charge-increase-decrease-remain-points?show=1816#a1816Thu, 03 Sep 2015 17:07:10 +0000Answered: If the electric field is constant in magnitude over the surface of a charged conductor, does that mean the charge is spread uniformly?
http://www.kemandi.com/1808/electric-constant-magnitude-surface-conductor-uniformly?show=1814#a1814
Yes!Physicshttp://www.kemandi.com/1808/electric-constant-magnitude-surface-conductor-uniformly?show=1814#a1814Thu, 03 Sep 2015 16:50:56 +0000Answered: What is the speed of the electron as it strikes the second plate?
http://www.kemandi.com/1801/what-the-speed-of-the-electron-as-it-strikes-the-second-plate?show=1812#a1812
<p><img alt="d=v_o t + (1/2)at^2" src="http://latex.codecogs.com/gif.latex?d%3Dv_o%20t%20&plus;%20%281/2%29at%5E2"></p>
<p><img alt=".02 = (1/2)a (1.5e8)^2" src="http://latex.codecogs.com/gif.latex?.02%20%3D%20%281/2%29a%20%281.5e8%29%5E2"></p>
<p>So, <img alt="a = 1.8e14 m/s" src="http://latex.codecogs.com/gif.latex?a%20%3D%201.8e14%20m/s"></p>
<p><img alt="v = v_0 + at = 1.8e14 * 1.5e-8 = 2.7e6 m/s" src="http://latex.codecogs.com/gif.latex?v%20%3D%20v_0%20&plus;%20at%20%3D%201.8e14%20*%201.5e-8%20%3D%202.7e6%20m/s"></p>
<p> </p>Physicshttp://www.kemandi.com/1801/what-the-speed-of-the-electron-as-it-strikes-the-second-plate?show=1812#a1812Thu, 03 Sep 2015 16:43:39 +0000