Physics - 8th Grade

A student graphs the motion of a toy car moving in a straight line over a 10-second time period.

Which statement best describes the motion of the car?

• The car moved at a speed of 5 meters per second and then moved at a slower speed during the next 5 seconds.

• The car moved at a speed of 5 meters per second and then moved at a faster speed during the next 5 seconds.

• The car moved at a speed of 1 meter per second and then moved at a slower speed during the next 5 seconds.

• The car moved at a speed of 1 meter per second and then moved at a faster speed during the next 5 seconds.

Tags

NGSS.MS-PS3-1

Two students push on the opposite sides of a crate, with the force applied by each student in newton (N), as shown in the diagram.

Assuming the crate is on a frictionless surface, describe the effect of these forces on the crate.

- Will the crate move toward the left, toward the right, or not at all.

- What is the direction and the magnitude of the net force on the crate?

Review the diagram carefully. Then enter your response in the box provided.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

A tennis ball is dropped down a stairwell.

Which statement BEST describes the energy of the tennis ball?

• The tennis ball's kinetic energy decreases as it fall to the ground.

• The tennis ball has the most potential energy just before it is dropped.

• The tennis ball has the most kinetic energy as soon as it is dropped.

• The tennis ball's potential energy increases as it falls to the ground.

Tags

NGSS.MS-PS3-1

NGSS.MS-PS3-5

This question has two parts.

A player hits a baseball with a baseball bat.

Part A

Which statement about the forces between the ball and the bat is correct?

• The force of the ball on the bat was less than the force of the bat on the ball.

• The force of the ball on the bat was equal to the force of the bat on the ball.

• The force of the ball on the bat was greater than the force of the bat on the ball.

Tags

NGSS.MS-PS2-1

Part B

Which statement BEST supports the answer to Part A?

• Whenever two objects interact, the more massive object always applies a greater force than the less massive object.

• Whenever two objects interact, the faster object always applies a greater force than the slower object.

• Whenever two objects interact, they always apply equal and opposite forces on each other.

• Whenever two objects interact, their forces always combine and are applied in the direction of the object that is moving the fastest.

Tags

NGSS.MS-PS2-1

A student sets a 0.4 kilogram (kg) soccer ball on the ground and gives it a hard kick. The ball traveled a distance of 37 meters (m). The acceleration of the ball was 2,550 meters per second squared (m/s²).

Based on the data, how much force in newtons (N) did the student apply to the ball?

• 14.8 N

• 68.9 N

• 1,020.0 N

• 6,375.0 N

Tags

NGSS.MS-PS2-2

A researcher observes a car speeding up from rest. The researcher records data about the car and the car's motion. Which data points can be used to calculate the net force that was acting on the car when it was speeding up?

Select TWO correct answers.

• The car's mass is 1,000 kg.

• The car's speed increased for 7 seconds.

• The car started from rest.

• The car's acceleration was 4 m/s².

• The car traveled a total of 300 m.

Tags

NGSS.MS-PS2-2

A car drives down a long road. A graph of the car's motion is shown.

What was the car's average speed in kilometers per minute for the entire 14-minute trip?

• 12 km/ min

• 0.86 km/ min

• 0.23 km/ min

• 1.17 km/ min

Tags

NGSS.MS-PS3-1