Momentum 5.1 Practice (PPC)

An experiment is conducted in which a cart travels across a horizontal surface and collides with a wall. Data collected from the experiment are used to create the graph of the cart’s velocity as a function of time. All frictional forces are considered to be negligible. Which data from the graph should the student use to determine the direction of the net force exerted on the cart and the direction of the change in momentum of the cart from the time intervals of A to B?

• The slope of the line from A to B, because that will provide information about the acceleration of the cart.

• The area bound by the curve and the horizontal axis from A to B, because that will provide information about the displacement of the cart.

• The difference in speed of the cart from A to B, because that will provide information about how the momentum of the cart changed.

• The graph cannot be used to make the determination, because the mass of the cart must be known in order to apply Δp =FΔt .

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

During an experiment, a toy car accelerates forward for a total time of 5s. Which of the following procedures could a student use to determine the average net force exerted on the car during the 5s that the car accelerates?

• Use a meterstick and stopwatch to measure the distance the car travels for the 5s .

• Use a balance to determine the mass of the car. Use a motion sensor to measure the speed of the car at a time of 0s and a time of 5s .

• Use a balance to determine the mass of the car. Use a meterstick to measure the distance the car travels for the 5s .

• Use a motion sensor to measure the speed of the car at a time of 0s and a time of 5s . Use a meterstick to determine the distance the car travels for 5s .

Tags

NGSS.HS-PS2-1

A cart is attached to a hanging block by a string that passes over a pulley, as shown in the figure. The pulley has negligible friction in its axle and negligible mass. A student must determine the change in momentum of the cart as it is pulled across the horizontal surface from the moment the cart is released from rest to the moment immediately before the cart collides with the pulley. Which of the following lists the measuring devices that are needed to determine the change in momentum of the cart?

• Timer

• Timer and mass balance

• Timer, mass balance, and meterstick

• Timer, mass balance, meterstick, and force probe

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

A student conducts an experiment in which a cart is pulled by a variable applied force during a 2 s time interval. In trial 1, the student exerts the force on a cart of mass M. In trial 2, the student exerts the force on a cart of mass 3M. In trial 3, the student exerts the force on a cart of 5M. In which trial will the cart experience the greatest change in momentum from 0 s to 2 s?

• Trial 1

• Trial 2

• Trial 3

• The change in momentum is equal for all three trials from 0 s to 2 s .

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

A toy car of mass 2kg travels along a horizontal surface with negligible friction at a speed of 1.0ms. The car then collides with a vertical wall. The wall applies a force of magnitude 20N for 0.2s on the toy car. Which of the following predicts the motion of the toy car immediately after the collision?

• The speed of the car will increase, and the car will travel in the opposite direction.

• The speed of the car will decrease, and the car will travel in the opposite direction.

• The speed of the car will remain the same, and the car will travel in the opposite direction.

• The car will stop and remain motionless.

Tags

NGSS.HS-PS2-1

A block of mass of 10kg travels in the positive direction along a surface with negligible friction. The block has an initial momentum 18kg⋅ms. The block collides with an object of an unknown mass that is at rest. The force exerted on the block as a function of time is shown on the graph. Which of the following best predicts the speed and direction of the block immediately after the collision?

• Speed increase, direction is the same.

• Speed decreases, direction is the same.

• Speed increases, direction is the opposite

• Speed decreases, direction is the opposite

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

Two objects of the same mass travel in opposite directions along a horizontal surface. Object X has a speed of 5m/s and object Y has a speed of 5m/s, as shown in the figure. After a period of time, object X collides with object Y. In scenario 1, the objects stick together after the collision. In scenario 2, the objects do not stick together after the collision.

Object X collides into object Y and exerts a force on object Y while both objects are in contact. A graph of the force that object X exerts on object Y is shown. How could the graph be used to determine the change in momentum of object Y during the collision?

• By multiplying the maximum force by the time during which the entire force was applied

• By dividing the maximum force by the time during which the entire force was applied

• By determining the magnitude of the slope of the line before 0.005s and after 0.005s

• By determining the area bound by the curve and the horizontal axis from 0s to 0.01s

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2

A block travels across a horizontal surface in which frictional forces are not considered to be negligible, as shown in the figure. Which of the following quantities should a student measure to verify that the direction of the frictional force exerted on the block from the surface is in the same direction as the change in momentum of the block? Select two answers. Justify your selections.

• The coefficient of friction between the block and the surface, because the force of friction is proportional to the coefficient of friction.

• The mass of the block, because the force of friction is proportional to the mass of the block.

• The initial velocity, because the initial momentum of the block is proportional to the final momentum of the block.

• The final velocity, because the initial momentum of the block is proportional to the final momentum of the block.

Tags

NGSS.HS-PS2-1

NGSS.HS-PS2-2