A stunt man jumps from the top of a tall platform and into a swimming pool below. His potential energy at the top is 10,000 J and at the water surface is zero. (a) What is his kinetic energy when his potential energy is 1,000 J? (b) What is his potential energy when his kinetic energy is 4,500 J? (ans: 9,000 J and 5500 J)

Work= force times distance: W=Fd  Part A: Calculate the work done in ligting a 460-N barbell 1.8m above the floor? express your anser to two significant figures and include the appropriate units.  PArt B: What is the gain of potential energy of the barbell when it is lifted to this height?

4. This Olympic skeleton athlete slides down an icy track head first. The track has many twists and turns with a total height of 102.75 m. If the 99.375 kg man has a speed of 27 m/s at the bottom, what was the total work done on him by friction and air resistance slowing him down? (In other words, what was the energy lost to friction and air resistance?) He starts from rest at the top. 6.3843e4 Previous submissions: -63.84 63.84 63843 J J incorrect

please help me with this

A roller-coaster car of mass 1.50 × 103 kg is initially at the top of a rise at point Ⓐ. It then moves 35.0 m at an angle of 50.0° below the horizontal to a lower point Ⓑ. (a) Find both the potential energy of the system when the car is at points Ⓐ and Ⓑ and the change in potential energy as the car moves from point Ⓐ to point Ⓑ, assuming y = 0 at point Ⓑ. (b) Repeat part (a), this time choosing y = 0 at point Ⓒ, which is another 15.0 m down the same slope from point Ⓑ.

A crane slowly lifts a 263 - kg crate a vertical distance of H = 13.0 m. mg crane F crane (a) How much work does the crane do on the crate? Enter to 3 significant figures W H 0 33,500 (b) How much work does the gravity do on the crate? Enter to 3 significant figures X√J XVI W gravity (c) What is the total work done on the crate? Enter to 3 significant figures ✓J W total = -33,500

You are given a cart with mass m and initial velocity v at the top of a ramp that is h meters high. If m=250 kg, v=10m/s and h= 100m, calculate the kinetic energy, potential energ, speed, and total energy at heights h, 3h/4, h/2,h/4 and 0

A 76.0-kg hiker is descending a mountain that has a peak altitude of 2350 m above sea level. The hiker has a device that measures her potential energy, and when she is at the peak of the mountain she decides to "zero" it (that is, she set's the zero point of potential energy to be the mountaintop). What does her potential energy device read sometime later on her descent when she is 1960 m above sea level?

A 0.27-kg stone is held 1.2 m above the top edge of a water well and then dropped into it. The well has a depth of 5.6 m.   (a) Taking y = 0 at the top edge of the well, what is the gravitational potential energy of the stone–Earth system before the stone is released? (b) Taking y = 0 at the top edge of the well, what is the gravitational potential energy of the stone–Earth system when it reaches the bottom of the well? (c) What is the change in gravitational potential energy of the system from release to reaching the bottom of the well?

A basketball playet makes a jump shot. The 0.600 kg ball is released at a height of 2.08m above the floor with a speeed of 7.31 m/s. The ball goes through the net 3.10 m above the floor at a speed of 4.03 m/s. What is the work done by the ball by air resistance, a nonconservative force  ?