# What is the kinetic energy of a 29 kg dog that is running at a speed of 7.9 m/s (about 18 mi/h)?

45,322 questions, page 353
1. ## physics

You're on a magic bridge floating 25 meters above a lake.  You through a rock at an angle of sixty degrees.  It takes 5.8 seconds for the rock to reach it's highest point. (a)  With what speed did you throw the rock? (b)  How far away from the bridge

asked by Nicole on March 15, 2012
2. ## physics

A body of mass 0.4kg moving with constant speed of 10m/s to north is subjected to a constant force of 8 N directed towards the south for 30s. Take the instant the force is applied to be t=0, the position of the body at that time to be x=0 and t =-5s and

asked by jeet mali on October 24, 2015
3. ## physics

A barefoot field-goal kicker imparts a speed of 47 m/s to a football initially at rest. If the football has a mass of 0.6 kg and the time of contact with the ball is 0.024 s, what is the magnitude of the force exerted by the ball on the kicker’s foot?

asked by Anonymous on May 5, 2013
4. ## physics

A hammer weighing of 1 kg moving with the speed of 10 m/s strikes the head of the nail driving it 10 cm into wall. Neglecting the mass of the nail, calculate: 1) The acceleration during the impact 2) The time interval during the impact 3) The impulse

asked by Anonymous on June 25, 2017
5. ## Precalculus

The instruments with an aircraft show that it is headed east with an airspeed of 180 mph. After 2 hours, the aircraft is actually 375 miles east and 20 miles north of its starting point. Find the wind speed and its direction.

asked by Merry on March 26, 2017
6. ## physics

A 15.7-g bullet is fired from a rifle. It takes 3.00 × 10-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 779 m/s. Assuming that the acceleration of the bullet is constant, find the average net force exerted

asked by trish on December 16, 2015
7. ## physics

A sinusoidal wave on a string is described by the equation y = (0.169 m) sin (0.713 x - 41.9 t), where x and y are in meters and t is in seconds. If the linear mass density of the string is 10.1 g/m ... a) ... the phase of the wave at x = 2.27 cm and t =

asked by maria on October 24, 2011
8. ## physics

Two ice skaters approach each other at right angles. Skater A has a mass of 30.7 kg and travels in the +x direction at 2.64 m/s. Skater B has a mass of 109 kg and is moving in the +y direction at 1.29 m/s. They collide and cling together. Find the final

asked by luma on December 20, 2015
9. ## physics

the solid fuel rocket boosters used to launch the space shuttle are able to lift the shuttle 45 kilometers above earths surface. During the 2.00 min that the boosters operate, the shuttle accelerates from rest to a speed of nearly 7.50 x 10^2 m/s. What is

asked by NoNo100 on September 15, 2009
10. ## Physics

An object of mass M = 1,338 g is pushed at a constant speed up a frictionless inclined surface which forms an angle θ = 50 degrees with the horizontal. Incline is increasing. What is the magnitude of the force that is exerted by the inclined surface on

asked by Nala on October 14, 2009
11. ## physics

In the figure below, a constant force of magnitude 82.0 N is applied to a 2.55 kg shoe box at angle = 64.5°, causing the box to move up a frictionless ramp at constant speed. How much work is done on the box by a when the box has moved through vertical

asked by Anonymous on October 14, 2012
12. ## math

ryan left the science museum and drove south gabriel left three hours later driving 42mph faster in s effort to catch up. after 2 hours gabriel finally caught up. find ryans speed

asked by corinne on November 18, 2009
13. ## Physics

Pam, wearing a rocket pack, stands on frictionless ice. She has a mass of 44 kg. The rocket supplies a constant force for 22.0 m, and Pam acquires a speed of 62.5 m/s. Assume that air resistance is negligible. (a) What is the magnitude of the force?

asked by Dar on February 18, 2010
14. ## physics

Please help! it has to do with momentum A 70 k/g woman and her 35 k/g son are standing at rest on an ice rink. They push against each other for .60 s, causing them to glide apart. The speed of the woman immediately after they separate is .55 m/s question

asked by marissa! on January 12, 2012
15. ## Physics

An automobile travelling with a speed of 60km/hr, can apply brake to stop within a distance of 20m. If the car is going twice as fast then calculate the stopping distance and stopping time? (b) Given R1 = 5.0 ± 0.2 and R2 = 10.0 ± 0.1. calculate the

asked by Shrawan on July 15, 2011
16. ## Physics(Urgent)

Using Planck's constant as h=6.63 E-34 J*s, what is the wavelength of a proton with a speed of 5.00 E6 m/s? The mass of the proton is 1.66 E-27 kg. Remember to identify your data, show your work, and report the answer using the correct number of

asked by Hannah on October 23, 2009
17. ## physics

An engineer must design a runway to accommodate airplanes that must reach a ground velocity of 60 m/s before they can take off. These planes are capable of being accelerated uniformly at the rate of 2.1 m/s2. (a) How long will it take the planes to reach

asked by miranda on October 23, 2012
18. ## physics

Two boat landings are 3.0 km apart on the same bank of a stream that flows at 1.6 km/h. A motorboat makes the round trip between the two landings in 50 minutes. What is the speed of the boat relative to the water? How do I factor in the fact that velocity

asked by Sally on August 10, 2014
19. ## physics

A barefoot ﬁeld-goal kicker imparts a speed of 44 m/s to a football initially at rest. If the football has a mass of 0.49 kg and the time of contact with the ball is 0.028 s, what is the magnitude of the force exerted by the ball on the kicker’s foot?

asked by Lindsey on December 6, 2013
20. ## Physics

A 15 kg box is given an initial push to start it moving up a frictionless ramp with angle theta = 30 degree and length delta r = 22m. What horizontal force F will keep the box moving with constant speed to the top of the ramp?

asked by Mary on December 4, 2016
21. ## physics

an aeroplane has a mass of 15 tonnes. At cruising speed,air flows over the top of it's wing at 150 m/s and under the wing at 120m/s. Calculate the pressure in difference between the top and the bottom of the wing and the surface area underside the wing

asked by Kay on November 25, 2016
22. ## physics

A person swings a 0.33 kg tether ball tied to a 5.4 m rope in an approximately horizontal circle. (a) If the maximum tension the rope can withstand before breaking is 11 N, what is the maximum angular speed of the ball? --I figured out the rest of the

asked by John on March 6, 2010
23. ## Physics

In the absence of air resistance, a projectile is launched from and returns to ground level. It follows a trajectory similar to that in the figure below and has a range of 15 m. Suppose the launch speed is doubled, and the projectile is fired at the same

asked by Anonymous on September 18, 2012
24. ## Physics Help

On the Acme W&W company production line, parts have to be transported 100 m by conveyor belt to a machine area. The parts move at a constant speed of 2.5 m/s. How much time does it take to move a part 100 m? Show steps please! Thank you!

asked by Tim on September 11, 2014
25. ## Physics

An object of mass M = 1,338 g is pushed at a constant speed up a frictionless inclined surface which forms an angle θ = 50 degrees with the horizontal. Incline is increasing. What is the magnitude of the force that is exerted by the inclined surface on

asked by Nala on October 14, 2009
26. ## Physics

A 21.3-g bullet is fired from a rifle. It takes 3.77 × 10-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 779 m/s. Assuming that the acceleration of the bullet is constant, find the average net force exerted

asked by Kendall on October 11, 2012
27. ## Physics

Using Planck's constant as h=6.63 E-34 J*s, what is the wavelength of a proton with a speed of 5.00 E6 m/s? The mass of the proton is 1.66 E-27 kg. Remember to identify your data, show your work, and report the answer using the correct number of

asked by Hannah on October 23, 2009
28. ## physics

Starting at rest at the edge of a swimming pool, a 72.0 kg athlete swims along the surface of the water and reaches a speed of 1.10 m/s by doing the work Wnc1 = +165 J. Find the nonconservative work, Wnc2 done by the water on the athlete. Thanx in advance.

asked by jawn on October 21, 2009
29. ## Physics I (Classical)

At some instant, a particle traveling in a horizontal circular path of radius 7.50 m has a total acceleration with a magnitude of 16.0 m/s^2 and a constant tangential acceleration of 12.0 m/s^2. Determine the speed of the particle at this instant and (1/8)

asked by Victoria on June 5, 2016
30. ## physics

When will your apparent weight be greatest, as measured by a a scale in a moving elevator; when the elevators: (a) accel. downward (b) accel. upward (c) is in free fall (d) moves upward at a constant speed? In what case would you weight be the least? When

asked by Sasha on October 26, 2009
31. ## College Physics

A 0.35 kg stone attached to a 0.8 m long string is rotated in a horizontal plane. The string makes an angle of 20° with the horizontal. Determine the speed of the stone. I've tried tan 20= gr/v^2 = (9.8)(.8)/v^2 = 4.7 m/s and that's not the correct answer

asked by Taylor on October 10, 2012
32. ## PHYSICS

Suppose that the magnetic field in the figure below has a magnitude of 1.1 T, the rod has a length of 0.86 m, and the hand keeps the rod moving to the right at a constant speed of 3.4 m/s. If the current in the circuit is 0.044 A, what is the average power

asked by Andrea on March 14, 2013
33. ## physics

A projectile of mass 0.803 kg is shot straight up with an initial speed of 24.8 m/s. (a) How high would it go if there were no air resistance? (b) If the projectile rises to a maximum height of only 9.36 m, determine the magnitude of the average force due

asked by blake on March 12, 2015
34. ## Physics

A 24.8-g bullet is fired from a rifle. It takes 2.15 × 10-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 778 m/s. Assuming that the acceleration of the bullet is constant, find the average net force exerted

asked by Chris on March 1, 2015
35. ## physics

A 22.4-g bullet is fired from a rifle. It takes 3.37 × 10-3 s for the bullet to travel the length of the barrel, and it exits the barrel with a speed of 740 m/s. Assuming that the acceleration of the bullet is constant, find the average net force exerted

asked by Anonymous on October 7, 2012
36. ## Personal fitness

2._____ training must target the muscle group that is needed for the activity you are training for. the best way to train your body to be able to do more push ups is to do push ups. (1 point) muscular endurance. cardio strength. aerobic. speed.

asked by Anonymous on October 21, 2013
37. ## college algebra

When a ball is thrown up into the air, it makes the shape of a parabola. The equation S= -5t^2 + v*t + k gives the height of the ball at any time, t in seconds, where “v” is the initial velocity (speed) in ft/sec and “k” is the initial height in

asked by renee on March 29, 2010
38. ## Math

a small plane flies due south with a speed of 112 m/s while a tailwind blows due south at 31 m/s. Draw and label a vector diagram and calculate the magnitude and direction of the plane's resultant velocity

asked by Penn on September 25, 2016
39. ## physics

A car goes round a flat circular bend whose radius is 100metres at constant speed at 30 metres per second. Calculate its acceleration? If the mass of the car is 1500kg.calculate the frictional force required to provide the acceleration

asked by nerea on April 24, 2018
40. ## physics

An artillery shell is launched on a flat, horizontal field at an angle of a = 43.5° with respect to the horizontal and with an initial speed of v0 = 263 m/s. What is the horizontal distance covered by the shell after 6.77 s of flight? What is the height

asked by qwertzuiop on February 1, 2012
41. ## physics

A 25 g bullet is fired from a gun into a 1.35 kg block of wood initially at rest. (The bullet sticks in the wood). The wood is driven 9.5 m across a horizontal surface with coefficient of friciton 0.25. Find the speed of the bullet just before impact.

asked by ashley on November 30, 2012
42. ## phsics

An artillery shell is launched on a flat, horizontal field at an angle of α = 31.5° with respect to the horizontal and with an initial speed of v0 = 266 m/s. What is the horizontal distance covered by the shell after 9.44 s of flight? What is the height

asked by Anonymous on September 22, 2010
43. ## physics

A hose ejects water at a speed of 2m/s through a hole of area 0.01m2.if the water strikes a wall normally,calculate the force on the wall in Newtons,assuming the velocity of water nomal to wall is zero after collision.

asked by mariam on February 16, 2012
44. ## physics

A racing car reaches a speed of 40 m/s. At this instant, it begins a uniform negative acceleration, using a parachute and a braking system, and comes to rest 5.0 s later. (a) Determine the acceleration of the car. (b) How far does the car travel after

asked by Tamera on September 7, 2012
45. ## physics

An artillery shell is launched on a flat, horizontal field at an angle of α = 31.5° with respect to the horizontal and with an initial speed of v0 = 266 m/s. What is the horizontal distance covered by the shell after 9.44 s of flight? What is the height

asked by Anonymous on September 22, 2010
46. ## phy 231

An artillery shell is launched on a flat, horizontal field at an angle of α = 40.5° with respect to the horizontal and with an initial speed of v0 = 338 m/s. a.What is the horizontal distance covered by the shell after 8.09 s of flight? b.What is the

asked by Help plz on January 24, 2016
47. ## Math

Cities A, B, C and D are equidistant. That is, B is d miles from A, C is d miles from B, and D is d miles from C. Suppose you travel 55 mph from A to B, 40 mph from B to C, and 50 Mph from C to D. What single, constant speed could you have traveled from A

asked by Anonymous on May 4, 2011
48. ## physics

An artillery shell is launched on a flat, horizontal field at an angle of a = 43.5° with respect to the horizontal and with an initial speed of v0 = 263 m/s. What is the horizontal distance covered by the shell after 6.77 s of flight? What is the height

asked by qwertzuiop on February 2, 2012
49. ## Physics

The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.8 m. The magnetic field of the generator is 0.21 T, and the coil rotates at an angular speed of 26 rad/s. What is the peak emf of

asked by Ashley on March 17, 2013
50. ## Physics - URGENT

A ball is thrown horizontally of a cliff. If the initial speed of the ball is 17 m/s and the cliff is 77 m high, how far from the base of the cliff will the ball land in the water below? Calculate the answer in meters (m) and rounded to three significant

asked by Anonymous on September 16, 2015
51. ## physic

A rock is thrown upward from the level ground in such a way that the maximum height of its flight is equal to its horizontal range R. (a) At what angle is the rock thrown? (b) Would your answer to part (a) be different if the rock is thrown with the same

asked by giz on October 1, 2015
52. ## Physics

The coil of a generator has a radius of 0.12 m. When this coil is unwound, the wire from which it is made has a length of 5.8 m. The magnetic field of the generator is 0.21 T, and the coil rotates at an angular speed of 26 rad/s. What is the peak emf of

asked by Ashley on March 17, 2013
53. ## physics

The tires of a car make 58 revolutions as the car reduces its speed uniformly from 92 to 33 . The tires have a diameter of 0.86 . What was the angular acceleration of the tires? If the car continues to decelerate at this rate, how much more time is

asked by juana on May 26, 2011
54. ## physics

An artillery shell is launched on a flat, horizontal field at an angle of α = 31.5° with respect to the horizontal and with an initial speed of v0 = 266 m/s. What is the horizontal distance covered by the shell after 9.44 s of flight? What is the height

asked by Anonymous on September 22, 2010
55. ## physics

The barrel of a rifle has a length of 0.97m. A bullet leaves the muzzle of a rifle with a speed of 601m/s. What is the acceleration of the bullet while in the barrel?

asked by emily on September 27, 2014
56. ## Math

A car is accelerated from rest to a speed of 35m/s over a distance of 18m. What is the car's acceleration? okay so I thought that I need to use the a= Vf-Vi/T2-T1. 18m-0s/35m/s-0s = 0.5?? I don't think I did this right.

asked by Physics on September 27, 2016
57. ## Phyics

A projectile is fired horizontally from a 39 m cliff at 30m/s . Find the speed and velocity of the projectile when it strikes the ground. Find vx Find vy Find v

asked by Eman on October 12, 2011
58. ## physics

a projectile is fired at 50 meters per second at an angle of 30 degrees below the horizontal off a cliff that is 50 meters high. How far away and at what speed and angle will this projectile land?

asked by Joanne on November 2, 2014
59. ## physics

A VW Beetle goes from 0 to 59.0 mi/h with an acceleration of +2.35 m/s2. (a) How much time does it take for the Beetle to reach this speed? (b) A top-fuel dragster can go from 0 to 59.0 mi/h in 0.700 s. Find the acceleration (in m/s2) of the dragster.

asked by gary on September 18, 2012
60. ## Algebra

A boat traveled from Pier A to Pier B with the current in 2 hours. How far from each other are these piers, if the return trip took 6 hours, and the current speed is 2.5 mph?

asked by Anish Panda on February 27, 2016
61. ## physics

A locomotive is accelerating at 3.10 m/s2. It passes through a 25.0-m-wide crossing in a time of 3.03 s. After the locomotive leaves the crossing, how much time is required until its speed reaches 25.7 m/s?

asked by Anonymous on February 13, 2012
62. ## Physics

A VW Beetle goes from 0 to 46.0 mi/h with an acceleration of +2.35 m/s2. (a) How much time does it take for the Beetle to reach this speed? (b) A top-fuel dragster can go from 0 to 46.0 mi/h in 0.750 s. Find the acceleration (in m/s2) of the dragster.

asked by Shelby on September 12, 2016
63. ## physics

a 60-kilogram astronaut floating in space outside the capsule throws his 0.50-kilogram hammer such that it moves with a speed of 10 m/s relative to the capsule. what happens to the astronaut?

asked by Ted on March 30, 2015
64. ## math

paul can type 60 words per minute and jenifer can type 80 words per minute how does pauls typing speed compare to jenifers

asked by james on August 15, 2015
65. ## SCIENCE; Physics

A ball is dropped from a cliff amd has an acceleration of 9.8 meters per second squared. How long will it take the ball to reach a speed of 24.5 meters per second squared (m/s^2) ?

66. ## physics

A propeller blade has a period of rotation of 0.400s. What is the speed of the outer tip of the propeller blade if the tip is 1.20m from the hub?

asked by jane on November 7, 2010
67. ## physics

A Christmas tree ball will break if dropped on a hardwood floor with a speed of 2.0 m/s or more. If it falls 15 cm from a tree branch to the floor, will it break?

asked by Anonymous on September 27, 2011
68. ## Physics

Can someone help with this calculation, please? A golf ball is hit at a 35 degree angle and the hole is 175m away. What is the speed of the ball necessary to hit the hole? Thank you for any help you can give-

asked by Anthony on October 9, 2010
69. ## physcis

a particle moving at a velocity of 6 m/s in the positive x direction is given an acceleration of 3.9m/s^2 in the positive Y direction for 3.4s. what is the final speed of the particle? answer in units of m/s

asked by vanessa on December 11, 2010
70. ## calsulus

if h(t) represents the height of an object above ground level at time t and h(t) is given by h(t)=-16t^2+13t+1 find the height of the object at the time when the speed is Zero. h(t)=?

asked by Jenny on September 14, 2010
71. ## Physics

A particle moving at a velocity of 4.8 m/s in the positive x direction is given an acceleration of 3.4 m/s2 in the positive y direction for 4.4 s. What is the ﬁnal speed of the particle? Answer in units of m/s.

asked by Holly on October 11, 2016
72. ## Physics

A bullet with mass 0.40 kg is fired with an initial velocity of 400 m/s from a gun with mass 5.0 kg. The speed of the reoil of the gun is? Do I have to 0.40 and 5.0 an then divide that by 400?

asked by Abbey on October 11, 2009
73. ## Physics

A particle moving at a velocity of 8 m/s in the positive x direction is given an acceleration of 7.4 m/s2 in the positive y direction for 1.7 s. What is the final speed of the particle? Answer in units of m/s

asked by hai on November 20, 2014
74. ## Math

Trisha rides her bike 5 miles on Saturday in 30 minutes. She rides another 13 miles in one hour. What is the average rate of her speed on Saturday?

asked by Kiki on February 26, 2016

You're given a ramp 0.5m in height with a 3m incline. A mass of 1kg is at the top of the ramp and there is a friction of 2N. If the ramp has a force of friction of 2N, what will the speed at the bottom of the ramp be?

asked by Elena on November 23, 2010
76. ## Calculus

If h(t) represents the height of an object above ground level at time t and h(t) is given by h(t)=-16t2+11t+1 find the height of the object at the time when the speed is zero.

asked by Melissa on September 13, 2010
77. ## Math

Yolanda walked a distance of 3 miles in 90 minutes. If her speed for the first mile was 6 miles per hour, how many minutes did it take her to walk the rest of the distance.

asked by Nick on September 4, 2011
78. ## pysic

A 328 kg car moving at 19.1 m/s hits from behind another car moving at 13.0m/s in the same direction. If the second car has a mass of 790kg and a new speed of 15.1m/s what is the velocity of the first car after the collision?

asked by paul on July 21, 2010
79. ## physics

A locomotive is accelerating at 2.0 m/s2. It passes through a 20.0-m-wide crossing in a time of 2.8 s. After the locomotive leaves the crossing, how much time is required until its speed reaches 36 m/s?

asked by Danny on September 10, 2011
80. ## science

Light waves are traveling through glass. If the wavelength of some part of the light wave is 4 x 10-7 m and the frequency of that light is 5 x 1014 Hz, what is the speed of light through the glass?

asked by Bri on February 5, 2018
81. ## physics

a ford is traveling with a speed of 15 m/s and is 200 meters ahead of a Chevy traveling in the same directin at 20 m/s. How far will the Chevy travel before catching up to the Ford?

asked by Beth on September 25, 2012
82. ## physics

A bus of mass 2500kg goes round a corner of radius 50m at a speed of 5m/s. what force is needed for the bus to go round the corner?

asked by Physics on January 26, 2016
83. ## chem urgent!!

At a temperature of 35 °C, fluorine gas effuses through a pinhole at a rate of 8.7 L s−1. What is the speed of the fluorine as it effuses through the pinhole? i no u use the eq. 3rt/M ^.5 but i get 20 for the answer but it is really 450.

asked by sam on June 11, 2008
84. ## physics

a bullet shot at 500 m/s into a block of wood of mass 0.49kg and becomes in-bedded in it. if it gives the block a speed of 11 m/s, find the mass of the bullet.

asked by josh anderson on February 22, 2011
85. ## physics

A beach ball rolling in a straight line toward you at a speed of 0.5 m/sec. Its momentum is 0.25kg m/sec. What is the mass of the beach ball?

asked by karen on January 23, 2014
86. ## math

You backpacked for a distance of 15.75 miles today. If you backpacked at an average speed of 1.26 miles per hour, how many hours did you spend backpacking today?

asked by matthew on April 29, 2019
87. ## physics

An ashtray slides across a table with a speed of 0.9 and falls off the edge. If it takes 0.4 s to reach the floor, how far from the edge of the table does the ashtray land?

asked by anonymous on March 11, 2014
88. ## Physics

A Gun of Mass 3.5kg fires a bullet at 320m/s. If the gun recoils with a speed of 24m/s, calculate the mass of the bullet.

asked by Jacob on February 16, 2015
89. ## physics

a car at rest accelrates unifosmly to a speed of 144 km 1 hour . How much distance is covered by the car. U=0, t=2 sec, v=144 km 1 hour

asked by sourav on August 22, 2012
90. ## physics

If a particle goes from location Xi = 10i + 5j + 2k to location Xf = 15i – 7j + 10k in a time ∆t = 5 sec. what is the average velocity and average speed of the particle?

asked by Ama on December 7, 2010
91. ## physics

sorry mr bob purlsey again to annoy you. so i did all my calculations and read about hooke's law yesterday and presented to my teacher. however i was not allowed to used hooke's law because we haven't learned it yet and i did not know how to connect

asked by physics(sorry) on June 14, 2007
92. ## Science

What is the main source of energy for the water cycle? What type of heat transfer does this provide? The sun is the main source driving it: Sun heats water, water evaporates. What type of heat transfer does it provide? I think that it is radiation, but I'm

asked by Emilie on January 16, 2007
93. ## physics

A 2.0kg bag is held by a string to the ceiling as shown in the diagram below. A 10-g bullet travelling at 200m/s strikes the stationary bag. The height of the bad after the collision is 10cm. Assuming there is no friction, determine the speed, in metres

94. ## physics

A pulley of radius .10 m and having a rotational inertia of .30 kg-m^2 has a cord wrapped around it and attached to a 6.00 kg mass as shown. The pulley is free to rotate about a fixed axis through its center. The mass is allowed to fall from rest. What is

asked by Anonymous on April 13, 2013
95. ## Physics

A pole-vaulter of mass 60.2 kg vaults to a height of 6.1 m before dropping to thick padding placed below to cushion her fall. (a) Find the speed with which she lands. (b) If the padding brings her to a stop in a time of 0.52 s, what is the average force on

asked by Ray on March 4, 2012
96. ## Physics

A physics teacher (mass = 84.5 kg) is jogging through the woods and runs straight into a large oak tree at 3.5 m/s. Rebound speed is measured at 2.3 m/s in the opposite direction. If the time of contact with the tree is 45 milliseconds, what is the

asked by Will on March 18, 2013
97. ## physics

A uniform stick 1.5 m long with a total mass of 210 g is pivoted at its center. A 3.9-{\rm g} bullet is shot through the stick midway between the pivot and one end The bullet approaches at 250 {\rm{ m}}/{\rm{s}} and leaves at 140 {\rm{ m}}/{\rm{s}}. With

asked by Anonymous on April 26, 2011
98. ## Physics

Three solid cylinder rods roll down a hill with the same linear speed. Rod R1 has a 1inch diamter, Rod R2 has a 2inch diameter, and Rod R3 has a 3inch diameter. They all have the same masses. Rank in order the rotational energies of R!, R2, and R3. a. E1 >

asked by Sandy on April 22, 2009
99. ## Science

During a football match, the ball shot towards the goal struck the defender's foot at the speed of 10m/s and it bounced back at 20m/s. If the time of impact was 0.2 sec, and mass of the ball 0.5 kg,then find the average force exerted by defender on the

asked by Kushagra on February 10, 2012
100. ## Physics

Three solid cylinder rods roll down a hill with the same linear speed. Rod R1 has a 1inch diamter, Rod R2 has a 2inch diameter, and Rod R3 has a 3inch diameter. They all have the same masses. Rank in order the rotational energies of R!, R2, and R3. a. E1 >

asked by Sandy on April 22, 2009