What force is the primary reason for the stopping process when a car applies its brakes to come to a screeching stop?

• A)gravity

• C)sliding friction

• B)magnetism

• D)rolling friction

Tags

NGSS.HS-PS2-1

A cup of coffee sits on the dashboard of an automobile. The car goes around a sharp curve. Even though you hold the cup still, coffee still splashes out.

This can best be explained due to

• A)density.

• B)friction.

• C)gravity.

• D)inertia.

Why does an object in motion stay in motion unless acted on by an unbalanced force?

• A)because forces are what stop and start motion

• B)because balanced forces cannot exist in nature

• C)because motion is the inherent state of all matter

• D)because motion, once begun, continues to accelerate

Tags

NGSS.HS-PS2-1

Imagine you are on the top of a mountain with four basketballs. The mass of the four basketballs are 100 kilograms, 200 kilograms, 300 kilograms, and 400 kilograms. If the basketballs rolled down the hill, which one would supply the greatest force at the bottom of the mountain (assume that their velocities were equal at the bottom of the mountain)?

• A)100 kilogram basketball

• C)300 kilogram basketball

• B)200 kilogram basketball

• D)400 kilogram basketball

Tags

NGSS.MS-PS2-2

NGSS.MS-PS2-4

Mutt and Jeff are running along a path each pushing a cart loaded with rocks. If Mutt's wagon has a mass two times greater than Jeff's and they want to stay together, arriving at their destination at the same time, what must happen?

• A)Jeff should slow down so Mutt can catch up.

• B)Mutt must use half as much force to push his cart.

• C)Mutt must use twice as much force to push his cart.

• D)Mutt and Jeff will use the same force, but Mutt will take bigger steps.

Tags

NGSS.HS-PS2-1

The law of inertia states that an object in motion will stay in motion, and an object at rest will stay at rest unless acted upon by an unbalanced force. Which law of motion is this describing?

• A)Newton's First Law

• B)Newton's Third Law

• C)The law of gravity

• D)Newton's Second Law

Consider the free body diagram. If the sum of the tension forces is equal to the force of gravity, which description BEST applies?

• A)A book is at rest on a tabletop.

• B)A physics student rests a backpack upon one shoulder.

• C)A girl hangs by both hands, motionless, from a trapeze.

• D)A girl falls slowly to Earth while strapped to a parachute.

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NGSS.MS-PS2-2

Consider the four masses. Describe the motion of the masses if you used THE SAME amount of force to move each one over THE SAME time.

• A)The greatest mass would not move at all.

• B)All four masses would move the same distance.

• C)The lower the mass, the greater the distance the mass would move.

• D)The greater the mass, the greater the distance the mass would move.

Tags

NGSS.MS-PS2-1

NGSS.MS-PS2-2

Brad and Erin decide to have a tug of war contest. Erin pulls the rope with all her might and so does Brad. Sadly, Brad only pulls with half the force that Erin pulls with. Sarah is watching and waiting for her turn. Since the forces are unbalanced the rope will move towards Erin. Using Newton's first law of motion as a model, explain how Brad could keep from losing the tug of war.

• A)Ask Erin to let go of the rope.

• B)Make the rope longer so Brad can get a better grip.

• C)Let Sarah, who pulls just as hard as Brad, team up with him to pull the rope together.

• D)Let Sarah, who pulls just as hard as Brad, team up with Erin to pull the rope together.

Tags

NGSS.MS-PS2-2

Meg and Rachel each have bowling balls with the same mass. They both roll them as hard as they can and then measure the speed of the balls.

Meg's ball and Rachel's ball were measured to have the exact same speed.

What do you know about the forces applied by the girls?

• A)Meg applied more force than Rachel.

• B)Rachel applied more force than Meg.

• C)They applied an equal amount of force.

• D)They applied a almost the same amount of force.

Tags

NGSS.MS-PS2-2