Assignment:
1. Answer the following questions:
•In your own words, describe the process of energy exchange with the spring (Without air resistance).
•When we add air resistance, is the rate at which energy is dissipated constant? (Think of drag, is it constant with velocity?)
•Draw two graphs which include kinetic energy, potential energy of the spring and total mechanical energy. The first graph is without air resistance, the second one with air resistance.
2. True or False:
•The function that describes potential energy increases/decreases linearly.
- True, False
•The work done on an object depends on the force and the distance the object travels.
- ?True, False
•Total mechanical energy increases with time in an isolated system, just like entropy.
- ?True, False
•Friction force changes depending on the force applied to the object.
- True, False
•According to Hooke's law, the force applied by a spring is opposite to the displacement.
- True, False
3. You make Kenny, who has a mass of 30 kg, go down a slide that is 1000 meters above the ?surface of the earth. While going down the slide, he experiences some friction. When he exits the slide at ground level, he has a velocity of 100 meters per second and dies. Find the work done by friction on Kenny. Is the sign on this value positive or negative? Why?
4. A spring with a 3 kilogram mass attached hangs straight down from a hook like in your lab setup, so that it stretches 1 centimeters due to the weight of the mass. What is the spring constant?