1. A car traveling 15 mph skids to a stop in 10 ft. If the speed of the car were tripled to 45 mph, how far would the car skid in coming to a stop? 2. A truck is trying to pull a heavy trailer. The truck pulls with a force of 10,000 N for 60 seconds, but is unable to move the trailer even a small distance. How much work does the truck do on the trailer? 3. You have the grand idea that the science building would be better situated if you moved it North by 4 meters. To accomplish this you go outside and push with a 200 N against the science building for 3 hours. Needless to say, the building does not move, but you have worked up a good sweat. How much work have you done? 4. A ball with a mass of 2.5 kg is dropped from a height of 50 m. How fast will the ball be moving when it's height is 32 m?

Formulas you need are (a) Work = Force applied times distance moved in the direction of that force, (b) change in energy = work applied.