To test the impact performance of a 10 cm thick gymnastics mat, a 20 kg cylindrical mass isdropped onto the mat from a height of 1 m above the mat. During the impact, the cylinder’s vertical velocity reaches zero at the instant the mat has compressed to only 4 cm thick. a. How much kinetic energy does the cylinder have at the instant just before it contacts the mat? b. What average vertical force does the mat exert on the cylinder during the impact, from contact until the cylinder’s vertical velocity is zero?

A 2.46 kg block moves along a frictionless surface with a speed of 7.83 m/s when it encounters a rough shallow hill, whose sides have a length of l=5.21 m. The hill is low enough so that the block can make it over the hill. Because the surface of the hill is rough (shown in orange in the figure), the block experiences a frictional force of 2.23 N while on the hill. a) What is the speed of the block after it traverses the hill?

You are working out on a rowing machine. Each time you pull the rowing bar (which simulates the oars) toward you, it moves a distance of 1.20 m in a time of 1.80 s. The readout on the display indicates that the average power you are producing is 102 W. What is the magnitude of the force that you exert on the handle? i 3

The potential energy of an interaction is given by U(x)=ax², where a = +6.4 J/m². Initial speed of a 0.79-kg object in this system is 2.63 m/s at x = 0. A. How far does the object travel before it reaches a speed of v = 0? Express your answer with the appropriate units. B. Does your answer in the previous part depend on whether the object is traveling in the positive or negative  direction? Yes, the answer in the previous part is for the object traveling in the negative x� direction, the distance for the object traveling in the positive x� direction is greater than the obtained result. Yes, the answer in the previous part is for the object traveling in the positive x� direction, the distance for the object traveling in the negative x� direction is greater than the obtained result. No, it does not depend on whether the object is traveling in the positive or negative x� direction.

if the gravitational potential energy is 120,000 J and the kinetic energy is 20,000 J at position A what is the total energy?

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e You are logged in as Gavin Ritcheson A football weighing 5 N is dropped from a height of 7.6 m above the ground. What is the kinetic energy of the ball just as it hits the ground? Answer: Next page C US 0 11 28

A box of mass 4.0 kg hangs by a cable from the ceiling of an elevator. The elevator is moving up at a steady speed of 5.0 m/s for 8.0 m. Use g = 10 m/s2. Match the answers with questions. the final kinetic energy of the box (Kf)                                                                                              the change in kinetic energy of the box (ΔK) A. 320 J B. 20 J C. -320 J D. -20 J E. 50 J F. -50 J G. 0 J

Part A The cable of a crane is lifting a 950 kg girder. The girder increases its speed from 0.25 m/s to 0.75 m/s in a distance of 2.3 m. What is the girder's change in kinetic energy? Express your answer with the appropriate units. НА AK Value Units Submit Request Answer