Create complete models (descriptions, schema, force diagrams, position, ve- locity, acceleration and net force graphs, energy pie charts including work arrows if needed, mathematical quantities, motion maps, and assumptions where appropriate) for each of the systems described below. Make sure that your models are consistent and complete.

1. A surfer (m = 75 kg) is riding a series of waves that have a wavelength of 3 m and a period of 0.65 s. Unfortunately, he crashes into a canoe (m = 110 kg) that is only moving at 1.0 m/s (in the same direction as the surfer). Simplifying assumption: neither the surfer nor canoe feel any drag or friction with the water.

2- A wind generator is initially rotating with an angular velocity of 0.25 rad/s and blades that are 35.4 m long. Consider two situations: (a) when the generator is rotating with constant speed, and (b) when the operator applies a braking mechanism so that the blades stop moving completely in 120 s. The generator has a very large moment of inertia of I = 200,000 kg m2.

3-A spring-loaded potato gun is used to launch a 200 g potato across a level football field at an angle of 65. The spring in the potato gun has a spring constant of k = 2500 N/m and compresses a maximum distance of 0.10 m.

4-A motorcyclist (with total mass 175 kg) traveling at 31 m/s slams into the back of a bus (total mass 5100 kg), which is initially at rest. The motorcycle and bus then move off separately. Once it starts to move, the bus slides and feels a coefficient of kinetic friction of 0.45 between the ground and its tires. (Assume that the motorcycle does not feel friction before or after the collision, and that the collision is elastic.)

5- A 2 kg sign is placed on a spring in a store window to attract customers. When pulled down and released, the sign has a period of 8 s.