Momentum, Free Fall, and Projectile Motion Test

A 15,000 kg train car is moving at 2.4 meters/second and it collides with a 15,000 kg train car that is stationary. The two cars are hooked together and continue to move with a velocity of ___________ m/s.

• 36,000
• 3.6
• 0.42
• 1.2

A 3.00-kg cart with an initial velocity of +4.00 m/s collides inelastically with a 5.00-kg cart with an initial velocity of +2.00 m/s. The carts stick together when they collide. What is their speed after colliding?

• 0.75 m/s
• 2.00 m/s
• 2.75 m/s
• 3.00 m/s

A 45-kg boy throws a 0.50-kg ball at 15 m/s. Then, a 60-kg boy throws the same ball at 15 m/s. Which boy generates more momentum?

• Neither boy generates any momentum.
• The 45-kg boy generates more momentum.
• The 60-kg boy generates more momentum.
• Both boys generate the same amount of momentum.

The illustration shows the collision of two objects on a frictionless surface. What is the velocity of the two connected objects after the collision?

• 0 m/s
• 12.5 m/s
• 25 m/s
• 50 m/s

The table below lists the masses and velocities of several moving things. Which of the things listed has a momentum nearest that of a 0.145 kg baseball moving at a velocity of 45 m/s?

• Dog
• Truck
• Steel Pellet
• Toy Car

Match the statement below with its corresponding concept. " The momentum before is equal to the momentum after the interactions."

• The momentum is equal to zero.
• Momentum
• Momentum is conserved.

Match the idea below with its corresponding concept. "mass x velocity"

• The momentum is equal to zero.
• Momentum
• Momentum is conserved.

During a fall, why does a skydiver reach a terminal (constant) velocity and not continue to accelerate?

• The force of the skydiver on Earth is equal and opposite to the force of Earth on the skydiver.
• No forces act on the skydiver during the time the terminal velocity is reached.
• The downward force of air resistance on the skydiver equals the upward force of the weight of the skydiver
• The downward weight of the skydiver equals the upward force of air resistance on the skydiver.

A projectile is thrown directly upward at a velocity of 12.0 m/s. What is the projectile’s velocity at the maximum height before it begins to fall back toward Earth?

• 12.0 m/s
• 9.8 m/s
• 0 m/s
• 24.0 m/s

A projectile is thrown directly upward at a velocity of 12.0 m/s. What is the projectile’s acceleration at the maximum height before it begins to fall back toward Earth?

• 12.0 m/s/s
• 9.8 m/s/s
• 0 m/s/s
• 24.0 m/s/s