15) What is the average power output of a weight lifter who can lift 350 kg 2.0 m in 3.0 s? 16) A 1.00 x 10' kg sports car accelerates from rest to 20.0 m/s in 8.50 s. What is the average power output of the automobile engine? 17) Define Mechanical Energy. 18) A 5.00 kg ball falls from a height of 10.0 m. Just before hitting the ground, what will be its kinetic energy? 19) Which form of energy is stored in any compressed or stretched object? 20) A child riding a scooter has a total mass of 50.0 kg. The child is riding across the top of a frictionless hill that is 15.0 m high and 100.0 m long at 3.0 m/s. The child reaches the edge and coasts to the bottom without peddling. What is the child's velocity at the bottom of the hill? 21) A roller coaster car starts with an initial speed of 7.0 m/s from the top of a section of a track that is 100m tall. After traveling 50 m, it reaches the end of that section of the track and continues up the next section of the track. If this section of the track reaches a height of 40m, what will the car's speed be at top of the second section? Assume that you can neglect friction and that the car has no source of power. 22) A spring with force constant k=1000N/m is stetched a distance of 0.15m from equilibrium. What is the force required to stretch the spring 0.15m? From what height must a 2.0kg ball be dropped to compress the spring 0.15m? 23) A 2,500kg car traveling at 25m/s slams on the brakes and slows down to 15m/s. Calculate the work done by friction slowing the car down. If the car slows down over a distance of 50m, what is the average force of friction acting on the car?1) When does a force do work on an object? 2) A hill is 100 m long and makes an angle of 15 with the horizontal. As a 100 kg jogger runs up the hill, how much work does gravity do on the jogger? 3 ) Which form of energy is associated with an object in motion? 4) Which form of energy is associated with an object due to its position relative to Earth? 5) A horizontal force of 100 N is applied to move a 50 kg television set across a 100m level surface. What is the work done by the 100 N force on the television set? 6) A flight attendant pulls a 50.0 N flight bag a distance of 350.0 m along a level airport floor at a constant speed. A 30.0 N force is exerted on the bag at an angle of 40.0 above the horizontal. How much work is done on the flight bag? 7) If the only force acting on an object is friction during a given physical process, what assumption must be made in regard to the object's kinetic energy? 8) What is the kinetic energy of a 0.15 kg baseball thrown at 30.0 m/s? 9) What is the main difference between kinetic energy and potential energy? 10) An 80.0 kg climber hikes upward 14,495ft to the top of Mount Whitney(3.28ft=1m). What is the climber's gain in potential energy? 11) Why doesn't the principle of mechanical energy conservation hold in situations when frictional forces are present? 12) Old Faithful geyser in Yellowstone National Park shoots water every hour to a height of 40.0 m. With what velocity does the water leave the ground? (Disregard air resistance. g = 9.81 m/s'.) 13) A sled zips down an ice track starting at 100 m vertical distance up the hill. Disregarding friction, what is the velocity of the sled at the bottom of the hill? 14) List 3 equations for power