77. ssm A 2.00-kg rock is released from rest at a height of 20.0 m. Ignore air resistance and determine the kinetic energy, gravitational potential energy, and total mechanical energy at each of the following heights: 20.0, 10.0, and 0 m.

A center throws a basketball m = 1 kg straight up with an initial speed of vo = 9.5 m's. He releases the ball at shoulder | height ho = 1.9 m. Let gravitational potential energy be zero at ground level. Give the total mechanical energy of the ball E in terms of maximum height h it reaches, the mass m, and the gravitational acceleration g. E= What is the height, hm in meters? 9 HOME

A 2.35-kg object initially at rest has a gravitational potential energy of 74.6 J. Determine the speed of the object when it has moved under the influence of gravity to a location where its gravitational potential energy is 50.0 J. m/s

Isn't there a way to solve this by only using the work and energy?  W = F(Delta X)  W = 1/2mv_{final}^2-1/2mv_{initial}^2 Potential Energy = MGH  I understand how to solve this with regular FBD and newtons laws. I want to see the way to solve it using work and energy.

1. A 23.0 kg child is playing on a swing with a length of 2.5 m. If the swing starts from rest and makes an angle of 40.0◦ with the vertical at the top of the swing, a) determine the child’s speed at the bottom of the swing neglecting friction. b) If the swing has a speed of 2.8 m/s at the bottom, determine the work done by friction during the downswing and, bonus) assuming the force of friction is constant, determine the maximum angle the swing attains on the upswing after passing through the bottom. Hint: Use the approximation that cos θ ≈ 1 − 1 2 θ 2 for angles given in radians.