Matt ( m = 80 kg) and Trey ( m = 90 kg) slide across an ice skating rink and collide with each other. Before the collision, Matt was moving 3 m/s to...

Matt (m = 80 kg) and Trey (m = 90 kg) slide across an ice skating rink and collide with each other. Before the collision, Matt was moving 3 m/s to the east and Trey was moving 2 m/s to the west. After the collision, Matt is moving 1.5 m/s to the west.

a. What was the total momentum of the system before the collision? (1 point)

b. What is the total momentum of the system after the collision? (1 point)

c. What is Trey's speed after the collision? (1 point)

Bob throws a sticky piece of gum at a stationary cardboard box. The gum has a mass of 0.003 kg, and the box has a mass of 0.05 kg. The gum hits the box with a speed of 9 m/s, and they stick together and slide forward. 

a. What is the total momentum of the system before the collision? (1 point)

b. What is the total momentum of the system after the collision? (1 point)

c. What is the velocity of the gum/box combination after the collision? (1 point)

A projectile launcher has a mass of 3 kg. It fires a projectile of mass 0.08 kg horizontally at a speed of 300 m/s.

a. What is the total momentum of the system before the projectile is fired? (1 point)

b. What is the total momentum of the system after the projectile is fired? (1 point)

c. What is the recoil velocity of the launcher? (1 point)

Use Hooke's law to solve the following problems.

a. A spring with k = 11 N/m is stretched 0.25 m. What force does the spring apply? (1 point)

b. What is the spring constant of a rubber band that exerts a force of 35 N when it is stretched 0.1 m? (1 point

c. An elastic band has a spring constant of 55 N/m. It will break when the force reaches 2000 N. How far do you need to stretch the band for it to break? (1 point)

d. A 2 kg mass hangs motionless from a spring with spring constant 8 N/m. How far will the spring stretch if the mass is motionless? (1 point)

A spring with spring constant 40 N/m is compressed 0.1 m past its natural length. A mass of 0.5 kg is attached to the spring.

a. What is the elastic potential energy stored in the spring? (1 point)

b. The spring is released. What is the speed of the mass as it reaches the natural length of the spring? (1 point)

A pendulum has a mass of 3 kg and is lifted to a height of 0.3 m. What is the maximum speed of the pendulum? (1 point)

Question 13 (3 points)

Use the universal law of gravitation to solve the following problems.

a. Two cars of mass 3000 kg are 2 m apart. What is the force of gravity between them? (1 point)

b. The force of gravity between a planet and its moon is 371 N. If the planet has a mass of 4 × 1022 kg and the moon has a mass of 5 × 105 kg, what is the distance between their centers? (1 point)

c. The force of gravity between Tim and John is 1.85 × 10-9 N. If they are 18 m apart and Tim has a mass of 120 kg, what is John's mass? (1 point)