A 10.0-kg mass is dropped from a hot air balloon at a height of 325 m above the ground. Find its speed at points 300 m, 200 m, and 100m above the ground and as it hits the ground. (Use principle of conservation of Energy)

2.Find the maximum height reached by a ball thrown upward at a velocity of 95 ft/s.

3. A worker pulls a crate 10.0 m by exerting a force of 300 N. (a) How much work does the worker do? (b) How much work does the worker do pulling the crate a distance of 10.0 m by exerting the same force at an angle of 20.0 with the horizontal?

4. A roller coaster designer must carefully balance the desire for excitement and the need for safety. The most recent design is shown in Fig. 8.21. (a) If a 355-kg roller coaster car has zero velocity on the top of the first hill, determine its potential energy. (b) What is the velocity of the roller coaster car at the specified locations in the design? (c) Explain the relationship between velocity and the position on the track throughout the ride. (Consider the track to be frictionless.)

V= 0 m/s D C 60.0 m B 40.0 m 30.0 m 20.0 m A