In the high jump, the kinetic energy of an athlete is transformed into gravitational potential energy without the aid of a pole. a) With what minimum speed must athlete leave the ground in order to lift his center of mass 2.10 m and cross the bar with a speed of 0.50 m/s ?

A 98 kg bicyclist traveling 15 m/s coasts up a 5 m high incline. After reaching the top of the incline, their speed has been reduced to 2 m/s. How much thermal energy from friction was lost between the two points given?

A 3.6 g marble is fired vertically upward using a spring gun. The spring must be compressed 2.9 cm if the marble is to just reach a target 18 m above the marble's position on the compressed spring. (a) What is the change AU in the gravitational potential energy of the marble-Earth system during the 18 m ascent? (b) What is the change AU in the elastic potential energy of the spring during its launch of the marble? (c) What is the spring constant of the spring? (a) Number (b) Number ogres (c) Number Units Units Units

A cat's crinkle ball toy of mass 28 g is thrown straight up with an initial speed of 5 m/s. Assume in this problem that air drag is negligible. (a) What is the kinetic energy of the ball (in J) as it leaves the hand? (b) How much work is done (in J) by the gravitational force during the ball's rise to its peak? (c) What is the change in the gravitational potential energy of the ball (in J) during the rise to its peak? (d) If the gravitational potential energy is taken to be zero at the point where it leaves your hand, what is the gravitational potential energy (in J) when it reaches the maximum height? (e) If the gravitational potential energy is taken to be zero at the maximum height the ball reaches, what would the gravitational potential energy (in J) be when it leaves the hand? (f) What is the maximum height the ball reaches (in m)? m

A cat's crinkle ball toy of mass 15 g is thrown straight up with an initial speed of 3 m/s. Assume in this problem that air drag is negligible. (a) What is the kinetic energy of the ball as it leaves the hand? (b) How much work is done by the gravitational force during the ball's rise to its peak? (c) What is the change in the gravitational potential energy of the ball during the rise to its peak?

A center throws a basketball m = 1 kg straight up with an initial speed of vo = 9.5 m's. He releases the ball at shoulder | height ho = 1.9 m. Let gravitational potential energy be zero at ground level. Give the total mechanical energy of the ball E in terms of maximum height h it reaches, the mass m, and the gravitational acceleration g. E= What is the height, hm in meters? 9 HOME

A 50.2-g golf ball is driven from the tee with an initial speed of 58.0 m/s and rises to a height of 22.4 m. (a) Neglect air resistance and determine the kinetic energy of the ball at its highest point. (b) What is its speed when it is 7.23 m below its highest point? (a) Number (b) Number Units Units

In the figure, a block of mass m = 1.30 kg slides head on into a spring of spring constant k = 390 N/m. When the block stops, it has compressed the spring by 6.60 cm. The coefficient of kinetic friction between block and floor is 0.330. While the block is in contact with the spring and being brought to rest, what are (a) the work done by the spring force and (b) the increase in thermal energy of the block-floor system? (c) What is the block's speed just as the block reaches the spring?

"20 kg bear slides, from rest, 8 m down a Lodgepole Pine tree, moving with a speed of 5.6 m/s just before hitting the ground. What change occurs in the gravitational potential energy of the bear Earth system during the slide?"

A 700 kg dragster accelerates from rest to a final speed of 120 m/s in 400 m (about a quarter of a mile) and encounters an average frictional force of 1200 N. What is its average power output in watts and horsepower of the car engine?a) watts=  b) horsepower=