1. Some students conduct an experiment to prove conservation of momentum. They use two objects that collide. Measurements are taken before and after the collision.
Which quantities should be measured before and after the collision?
A. Velocity and time.
B. Mass and velocity.
C. Acceleration and time.
D. Mass and acceleration.
2. In a closed system, two moving bodies collide. There are no external forces acting on the system.
How does the total momentum of the system before the collision compare with the total momentum of the system after the collision?
A. The total momentum after the collision is zero, while the total momentum before the collision is nonzero.
B. The total momentum after the collision is less than the total momentum before the collision.
C. The total momentum after the collision is the same as the total momentum before the collision.
D. The total momentum after the collision is more than the total momentum before the collision.
3. As part of an experiment on momentum, a billiard ball with a mass of 0.180 kg travels 1.5 m in 0.5 s. What is the momentum of the ball?
A. 0.06 kg*m/s
B. 0.81 kg*m/s
C. 0.14 kg*m/s
D. 0.54 kg*m/s
4. Two students perform an experiment with soccer balls. They kick two soccer balls so that they collide. They measure the total momentum of the two soccer balls before and after the collision.
Which statement explains why the total momentum of the soccer balls before and after the collision may not be the same?
A. The soccer balls each have a different momentum after the collision than before the collision.
B.The system has external forces, such as friction and air resistance, acting on it.
C. The soccer balls exert forces on each other when they collide.
D. The system does not have any external forces.
5. Two students in bumper cars want to prove conservation of momentum. They collide their bumper cars. The first bumper car has a mass of 120 kg and was moving with a velocity of 4 m/s before the collision and with a velocity of −2 m/s after the collision. The second bumper car has a mass of 90 kg and was moving at a velocity of −5 m/s before the collision.
To prove conservation of momentum, what must be the velocity of the second bumper car after the collision?
A. 3.0 m/s
B. 2.3 m/s
C. 2.7 m/s
D. 1.0 m/s
15 answers
2. Mass and velocity.
3. V = 1.5m/0.5s = 3m/s.
M*V = 0.180kg * 3m/s = ___kg*m/s.
4. B.
5. Given: M1 = 120kg, V1 = 4m/s.
M2 = 90kg, V2 = -5m/s.
V3 = -2m/s = velocity of M1 after collision.
V4 = velocity of M2 after collision.
Momentum before = Momentum after
M1*V1+M2*V2 = M1*V3+M2*V4
120*4+90*(-5) = 120*(-2)+90V4
30 = -240+90V4
V4 = 3 m/s.
2. The total momentum after the collision is the same as the total momentum before the collision.
3. 0.54 kg⋅m/s
4. The system has external forces, such as friction and air resistance, acting on it.
5. 3.0 m/s