Physics - Ch. 7 - Momentum Quiz 1

A car weighing 12 kN is driving due north at 30.0 m/s. After driving around a sharp curve, the car is moving east at 13.6 m/s. What is the change in momentum of the car?

• 1.66 x 10⁴ kg·m/s east

• 13.6 kg·m/s east

• 1220 kg·m/s east

• 24.4 kg·m/s east

Two cars, each of mass 1300 kg, are approaching each other on a head-on collision course. Each speedometer reads 19 m/s. What is the magnitude of the total momentum of the system?

• 0 kg·m/s

• 25000 kg·m/s east

• 49000 kg·m/s east

• 37000 kg·m/s east

A system consists of three particles with these masses and velocities: mass 3.0 kg, moving north at 3.0 m/s; mass 4.0 kg, moving south at 5.0 m/s; and mass 7.0 kg, moving north at 2.0 m/s. What is the total momentum of the system?

• 3 kg·m/s north

• 1 kg·m/s east

• 2 kg·m/s west

• 4 kg·m/s south

Two particles, A and B, of equal mass are locate at some distance from each other. Particle A is at rest while B moves away from A at speed V. What happens to the center of mass of the system of the two particles?

• It does not move

• It moves with a speed V away from A.

• It moves with a speed V toward A.

• It moves with a speed ½V away from A.

• It moves with a speed ½V toward A.

Two uniform spheres with equal mass per unit volume are in contact with one another. The mass of sphere A is five times that of sphere B. The center of mass of the system is

• at the point where A and B touch.

• inside sphere B somewhere on the line joining the centers of A and B.

• inside sphere A somewhere on the line joining the centers.

• at the center of sphere A.

• outside of both spheres.

An object of mass m drops from rest a little above the Earth's surface for a time t. Ignore air resistance. After time t the magnitude of its momentum is

• mgt²

• mgt

• mg√t

• √tmg

• (mgt²)÷2

An object is launched straight upward in the +y-direction. Which graph shows the acceleration of a_y of the ball as a function of time? (Ignore air resistance)

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An object is launched straight upward in the +y-direction. Which graph shows the momentum p_y of the ball as a function of time? (Ignore air resistance)

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An object is launched straight upward in the +y-direction. Which graph shows the vertical position of the ball as a function of time? (Ignore air resistance)

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An object is launched straight upward in the +y-direction. Which graph shows the total energy of the ball as a function of time? (Ignore air resistance)

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