Physics Unit Test

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FIRST NAME

Class Period

• 4

• 7

A soccer ball comes to rest in the goal after being kicked. Which statement correctly describes the forces acting on the soccer ball when it is at rest?

• The forces are balanced so motion occurs.
• The forces are balanced so no motion occurs.
• The forces are unbalanced so motion occurs.
• The forces are unbalanced so no motion occurs.

The diagram below shows a swimmer in the ocean. The swimmer pushes against the water, and in turn, the water pushes the swimmer forward with 40 newtons of force. The ocean current also exerts 25 newtons of resistive force against the swimmer. Which statement most accurately describes the motion of the swimmer?

• The swimmer will stop moving in the ocean.
• The swimmer will stop, and then he’ll start moving again.
• The swimmer will continue moving forward in his current direction.
• The swimmer will move in the direction of the ocean current.

A train carrying coal is in motion on the train tracks. The diagrams below show different forces acting on the train as it accelerates. Which diagram shows forces acting on the train that would result in acceleration to the left?

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A police car travels 40 kilometers in 30 minutes. What is the average speed of the police car in kilometers per hour? Enter your answer below.

Part A According to Newton’s first law, what happens to the crate just after the vehicle stops?

• The crate moves forward at an increased speed.
• The crate moves backward at an increased speed.
• The crate moves forward at the same speed.
• The crate moves backward at the same speed.

Part B Which statement supports the answer to Part A?

• Friction is the force that acts in the opposite direction of motion.
• Inertia is the tendency for an object to resist a change in motion.
• Gravity is the force that pulls objects toward the center of Earth.
• Balanced forces do not result in a change in motion.

A student is practicing for a track meet. The coach records the time measurements during three trials. What is the student’s average speed in meters per second?

• 10.52 m/s
• 0.13 m/s
• 6.99 m/s
• 7.52 m/s