A 0.20-kg stone is held 1.3 m above the top edge of a water well and then dropped into it. The well has a depth of 5.0 m. Relative to the configuration with the stone at the top edge of the well, what is the gravitational potential energy of the stone–Earth system (a) before the stone is released and (b) 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?

1. Some species of whales can dive to depths of 800m. What is the total pressure they experience at this depth? (The density of sea water = 1020 kg/m, and 1 ATM =10$ N/m) A 15.0-kg object is pulled along a horizontal surface at a constant speed by a 25 N force acting at 30° above the horizontal. How much work is done by this force as the object moves 10.0 m? A force of F = 3i + 0.5j – 5k), N is applied to a particle located at r = 2i +4k, m. Determine a) The torque vector; b) The angle between the vectors F and r 3. 4. A ball of mass Mi = 0.250 kg and velocity Voi = +5.00 m/s collides head-on with a ball of mass M2 = 0.800 kg initially at rest. No external forces act on the balls. If the collision is perfectly inelastic, find the velocity of mi after collision? Voi M1 M2 2.

The drawing shows a bowling ball suspended from the ceiling of a classroom by a strong cord. The ball is drawn away from its equilibrium position and released from rest at the tip of a student's nose. The student remains stationary. After one swing when the ball returns toward the student, will it hit the student's nose? O No, because air resistance will remove some of the ball's kinetic energy, so ball will reach slightly lower. O Yes, because after one swing it returns even higher than it started. O Impossible to determine without knowing the height of the student's nose.

A child with a weight of 230 N swings on a playground swing attached to 1.80-m-long chains. What is the gravitational potential energy of the child-Earth system relative to the child's lowest position at the following times? (a) when the chains are horizontal (b) when the chains make an angle of 27.0° with respect to the vertical (c) when the child is at his lowest position