Force and Motion Review

Read the statements below and identify the direction and net force of the object. A box is being pulled by two people to the right. One person is pulling with a force of 6N and the other person is pulling with a force of 3N. The box will move with a net force of ___ to the ___.

• 9N, right

• 6N, left

• 3N, right

• 0N, no movement

Tags

NGSS.MS-PS2-2

A group of students was handed these 5 flashcards displayed. The students were then asked to identify how many of the flashcards are examples of balanced forces acting on an object. Based on the examples given, which of the flashcards represents balanced forces acting on an object? Choose TWO correct answers.

• A plane is traveling in a straight line at a constant speed.

• A car increases its speed from 20 m/s to 35 m/s.

• A runner is traveling on a curve during a race.

• A rock is at rest on the side of a busy highway.

• A truck traveling at 65 mph slams on its brakes.

The diagram shows a car moving to the right with a force of 35 newtons while the wind is blowing to the left with a force of 15 newtons. What is the net force acting on the car? Enter the correct answer in the box.

• 20 N

• 50 N

• 15 N

• 35 N

Tags

NGSS.MS-PS2-2

A student stands on a skateboard as the skateboard remains in place. When the student pushes his foot against the ground, the skateboard moves forward. The harder he pushes against the ground, the faster the skateboard moves. A friend jumps on for a ride, and the skateboard slows down. The student must push even harder to get the skateboard moving again. Once they get going, they hit a curb. The skateboard stops moving, but the students fly onto the grass. Fortunately, everyone is fine.

Which of the following describes an instance where unbalanced forces influenced the skateboard?

• The skateboard accelerates down a slope due to gravity.

• The skateboard moves at a constant speed on a flat surface.

• The skateboard is at rest on a flat surface.

• The skateboarder applies a force to stop the skateboard.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-5

A student stands on a skateboard as the skateboard remains in place. When the student pushes his foot against the ground, the skateboard moves forward. The harder he pushes against the ground, the faster the skateboard moves. A friend jumps on for a ride, and the skateboard slows down. The student must push even harder to get the skateboard moving again. Once they get going, they hit a curb. The skateboard stops moving, but the students fly onto the grass. Fortunately, everyone is fine.

Describe one instance in the above paragraph where the skateboard was under the influence of balanced forces. Identify the primary forces involved, and explain why they were balanced.

• When the skateboard is at rest on a flat surface.

• When the skateboard is accelerating downhill.

• When the skateboard is turning a corner.

• When the skateboard is moving at a constant speed on a flat surface.

Which of the following are indicators that an object is experiencing balanced forces? Select TWO correct answers.

• An object is changing its direction.

• An object is moving at a constant speed.

• An object is stationary (Not Moving).

• An object is speeding up.

• An object is slowing down.

When a car is on an icy roadway, it isn't easy to control its motion. Which of the following forces is responsible for this motion?

• balanced force

• equal force

• unbalanced force

• Newton's force

Tags

NGSS.MS-PS2-2

A car starts to skid on an icey road. Why is this due to an unbalanced force. Which statement BEST supports this answer?

• The spinning force of the tires pushes the car in the opposite direction.

• The input force exceeds the output force.

• The ice supplies an unbalanced force to the car's tires.

• The icy road does not supply enough friction to the car's tires.

Tags

NGSS.MS-PS2-2

Based on the available data in the table above, which of the following conclusions can be made about the amount of force used by each student during the race? Select TWO correct answers.

• Student B used the most force.

• Student D used the least force.

• Student A used more force than Student E.

• Student C used less force than Student A.

Tags

NGSS.MS-PS2-2

Newton's 3rd law of motion is summarized as action-reaction. For every action, there is an equal, but opposite reaction. This law is best demonstrated by -

• a baseball flying through the air

• a ball being dropped from the roof of a building

• going forward in your seat after the brakes are applied quickly

• the air rushing out of a balloon, causing it to move across the room

Tags

NGSS.MS-PS2-1