Physics TEST Corrections

(TEK 8.6(C)

A pitcher throws a ball toward a player holding a softball bat. The player uses the bat to hit the ball. The bat applies a 10-newton force to the ball.

Which statement correctly describes the reaction force between the bat and ball?

• The reaction force is the force that causes the ball to move toward the bat.

• The reaction force is the force applied to the bat by the player holding the bat.

• The reaction force is the force that pulls the ball toward the ground.

• The reaction force is the force of the ball on the bat.

TEK 8.6(C)

A large rock is motionless on a flat sidewalk. Which statement best explains why the rock remains motionless?

• There are no forces acting on the rock.

• The only force acting on the rock is directed toward the sidewalk.

• The forces acting on the rock are all balanced.

• The sidewalk exerts an unbalanced force on the rock.

Four boxes are sliding with constant speed before each box experiences an unbalanced force of 8 N. Which box would experience the greatest acceleration when the unbalanced force is applied?

• The box with a mass of 2 kg

• The box with a mass of 4 kg

• The box with a mass of 6 kg

• The box with a mass of 8 kg

TEK 8.6 (B)

Which of the following best describes the velocity of an object?

• 30 m/s

• 30 m east

• 30 m/s east

• 30 m/s²

TEK 8.2(E)

Two forces are applied to a 17 kg box, as shown. The box is on a smooth surface.

Which statement best describes the acceleration of the box?

• The box accelerates at 1.0 m/s² to the right because the net force is 17 N to the right.

• The box accelerates at 1.9 m/s² to the right because the greater force is to the right.

• The box accelerates at 3.0 m/s² because the combined forces cause the box to accelerate.

• The box does not accelerate, because neither force is large enough to move the box.

TEK 8.6(C)

Two cars with different masses travel at the same speed down a hill toward a stop sign. What will happen when both cars apply brakes at the same time to stop?

• The car with the smaller mass will require less force to stop than the car with the larger mass.

• The car with the larger mass will maintain its velocity while traveling down the hill.

• The car with the smaller mass will take longer to stop than the car with the larger mass.

• The car with the larger mass will have less inertia than the car with the smaller mass.

TEK 8.6(B)

What is the speed of the object represented by the graph?

• 0.5 m/s

• 2 m/s

• 5 m/s

• 10 m/s

TEK 8.6(A)

The diagram above shows a sled moving along a smooth, frictionless track.

In which sections of the track will the sled experience an unbalanced force?

• Sections 1 and 3

• Sections 2 and 3

• Sections 2 and 4

• Sections 3 and 4

TEK 8.6 (A)

Sometimes tectonic plates do not move easily past one another, and the plates become stuck. Forces build up, and when the plates finally move, tension is released, as shown above.

The sudden movement of the plates is caused by —

• the mass of the plates

• the weight of the plates

• unbalanced forces

• gravitational force

TEK 8.2(E)

A student lets a toy car roll four times down a ramp that is 1 m long. Each time the student covers the surface of the ramp with a different material. The student measures the time it takes the car to roll down the ramp and records the results in the table above.

Which of these would be the best conclusion based on the data in the table?

• Different surfaces affect how fast a toy car accelerates.

• Different toy cars travel at different speeds.

• Gravity has little effect on the speed of toy cars on different surfaces.

• Air resistance is the greatest factor in limiting the acceleration of different toy cars.