Question

1. A 7130-kg car is travelling at 24.8 m/s when the driver decides to exit the freeway by going up a ramp. After coasting 418 m along the exit ramp the car\'s speed is 12.4 m/s, and it is h = 12.5 m above the freeway. What is the magnitude of the average drag force exerted on the car?

2. The superheroine Xanaxa, with a mass of 66.3 kg, is in a hair-raising chase after the 74.3-kg arch-villain Lexlax. She leaps from the ground to the top of a 195-m-high building, then dives off and comes to rest at the bottom of a 16.7-m-deep excavation, where she finds Lexlax and neutralizes him. Does all this bring about a net gain or a net loss of gravitational potential energy? Loss or Gain

By how much? Answer with a positive number. Take g = 9.81 m/s2.

3.Tom has built a large slingshot, but it is not working quite right. He thinks he can model the slingshot like an ideal spring, with a spring constant of 75.0 N/m. When he pulls the slingshot back 0.305 m from a non-stretched position, it just doesn\'t launch its payload as far as he wants. His physics professor \"helps\" by telling him to aim for an elastic potential energy of 14.5 Joules. Tom decides he just needs elastic bands with a higher spring constant. By what factor does Tom need to increase the spring constant to hit his potential energy goal?

During a followup conversation, Tom\'s physics professor suggests that he should leave the slingshot alone and try pulling the slingshot back further without changing the spring constant. How many times further than before must Tom pull the slingshot back to hit the potential energy goal with the original spring constant?

4. An adult dolphin weighs around 1610 N. How fast must he be moving as he leaves the water vertically in order to jump to a height of 3.50 m? Ignore air resistance.

5. Nate the Skate was an avid physics student whose main non-physics interest in life was high-speed skateboarding. In particular, Nate would often don a protective suit of Bounce-Tex, which he invented, and after working up a high speed on his skateboard, would collide with some object. In this way, he got a gut feel for the physical properties of collisions and succeeded in combining his two passions.* On one occasion, the Skate, with a mass of 119 kg, including his armor, hurled himself against a 801-kg stationary statue of Isaac Newton in a perfectly elastic linear collision. As a result, Isaac started moving at 1.37 m/s and Nate bounced backward. What were Nate\'s speeds immediately before and after the collision? (Enter positive numbers.) Ignore friction with the ground. Before:_______m/s, After:_______m/s

*By the way, this brief bio of Nate the Skate is written in the past tense, because not long ago he forgot to put on his Bounce-Tex before colliding with the Washington Monument in a perfectly inelastic collision. We will miss him.

Answer 1