From the top of a cliff 80 meters high, a ball of mass 0.4 kilogram is launched horizontally with a velocity of 30 meters per second. The potential energy of the ball is zero at the bottom of the cliff.  Sketch the graphs of the potential, kinetic, and total energies of the ball as functions of time until it hits the ground.

Someone drops a 70 – g pebble off of a docked cruise ship, 50.0 m from the water line. A person on a dock 5.0 m from the water line holds out a net to catch the pebble. (a) How much work is done on the pebble by gravity during the drop? (b) What is the change in the gravitational potential energy during the drop? If the gravitational potential energy is zero at the water line, what is the gravitational potential energy (c) when the pebble is dropped? (d) When it reaches the net? What if the gravitational potential energy was 40.0 Joules at water level? (e) Find the answers to the same questions in (c) and (d). |

#6 i need help on, it is realted to question 5 above question 6.

You drop a 2.60 kg book to a friend who stands on the ground at distance D = 12.0 m below. If your friend's outstretched hands are at distance d = 1.50 m above the ground (see the figure), (a) how much work Wg does the gravitational force do on the book as it drops to her hands? (b) What is the change AU in the gravitational potential energy of the book-Earth system during the drop? If the gravitational potential energy U of that system is taken to be zero at ground level, what is U (c) when the book is released and (d) when it reaches her hands? Now take U to be 100 J at ground level and again find (e) Wg, (f) AU, (g) U at the release point, and (h) U at her hands. (a) Number i Units (b) Number i Units (c) Number i Units (d) Number i Units (e) Number i Units (f) Number i Units (g) Number i Units (h) Number i Units > > > > > > >