A 5-kg watermelon is dropped from rest from the roof of a 22-m tall building and feels no appreciable air resistance. (a) Calculate the work done by gravity on the watermelon during its displacement from the roof to the ground? (b) Just before it strikes the ground, what is the watermelons (i) kinetic energy and (ii) speed? (c) Which of the answers in parts (a) and (b) would be “different” if there were appreciable air resistance?

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 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  ?

A 1.80 kg snowball is fired from a cliff 12.0 m high. The snowball's initial velocity is 16.4 m/s, directed 27.0° above the horizontal. (a) How much work is done on the snowball by the gravitational force during its flight to the flat ground below the cliff? (b) What is the change in the gravitational potential energy of the snowball-Earth system during the flight? (c) If that gravitational potential energy is taken to be zero at the height of the cliff, what is its value when the snowball reaches the ground? (a) Number (b) Number (c) Number Units Units Units

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 bag of sand which acts as a counter weight for a stage set is suspended vertically by a rope of length L = 6.00 m and has a mass m = 132 kg. If a stagehand pushes the bag of sand a distance d = 5.00 m sideway: (a) the horizontal force needed in order to hold the bag at this position (b) the amount of work done on the bag by gravity as the stagehand pushes it to this position (Include the sign of the value in your answer.) (c) the amount of work done by the stagehand as he pushes the bag to this position (Include the sign of the value in your answer.)

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The question is attatched down below.

While doing a chin-up, a man lifts his body 0.40 m. (a) How much work must the man do per kilogram of body mass? (b) The muscles involved in doing a chin-up can generate about 70 J of work per kilogram of muscle mass. If the man can just barely do a 0.40-m chin-up, what percentage of his body's mass do these muscles constitute? (For comparison, the total percentage of muscle in a typical 70-kg man with 14% body fat is about 43%.)

A skier of mass 115 kg travels down a ski trail. Suppose the ski trail is not frictionless. (a) If the top of the trail is a height 180 m above the bottom, find the work done by gravity on the skier. J (b) If the skier has a speed of 36 m/s at the bottom of the hill, what is the work done by friction on the skier? (Assume the skier starts at rest at the top of the hill.) J