1) An astronaut is 100 m away from her spaceship doing repairs with a 10 kg wrench. The astronaut’s total mass is 90 kg and the ship has a mass of 1 x 104 kg. If she throws the wrench in the opposite direction of the spaceship at 10 m/s how ling would it take for her to reach the ship?
2) Two blocks collide on a frictionless surface. Afterwards, they have a combined mass of 10 kg and a speed of 2.5 m/s. Before the collision, one of the blocks was at rest. This block had a mass of 8 kg. What was the mass and initial speed of the second block?
3) Larry and Jerry are riding together in an amusement park bumper car a 10 m/s, with a total mass = 300 kg. They bump Marissa’s car, mass 125 kg, which is standing still.
a. Calculate the total momentum of the system before the collision.
b. After the elastic collision, the boys continue ahead with a speed of 4 m/s Calculate their new momentum.
c. Using the law of conservation of momentum, what must Melinda’s new momentum be?
d. How fast is Melinda’s car bumped across the floor?
4) Running at 2 m/s, Thrack, the 45 kg quarterback, collides with Donk, the 90 kg tackle, who is traveling at 7 m/s in the other direction.
a. Calculate the total initial momentum of the system.
b. Upon collision, Donk continues to travel forward at 1 m/s. Calculate his new momentum.
c. Using conservation of momentum, calculate Thracks’s new momentum. In which direction is he moving?
d. Calculate Thrack’s new velocity.
5) Serena Williams volleys a tennis ball hit to her at 30 m/s. She blasts to back to the other court at 50 m/s. A standard tennis ball has mass of 0.057 kg. If Serena applied an average force of 500 N to the ball while it was in contact with the racket, how long did the contact last?
6) In the below picture, the carts are moving on a level, frictionless track. After the collision, all three carts stick together. Determine the direction and speed of the combined carts after the collision.
7) The train engine and its four boxcars are coasting at 40 m/s. The engine train has mass of 5500 kg and the boxcars have masses, from left to right, of 1000 kg, 1500 kg, 2000 kg, and 3000 kg. If the train can shoot boxcars backwards at 30 m/s relative to the train’s speed, how many boxcars does the train need to shoot out in order to obtain a speed of 58.75 m/s?