Force and Motion

A push and a pull are two examples of which the following?

• a force

• velocity

• a law of motion

• a balanced force

Tags

NGSS.MS-PS2-1

What term identifies a force that opposes motion and acts between two objects that are touching?

• inertia

• gravity

• friction

• balanced force

Four students used spring scales to measure the force needed to pull blocks made of different materials up a smooth ramp. All of the blocks moved at the same rate. The students recorded the force needed to move the different blocks: 6 N, 8 N, 7 N, and 5 N. Which of the following is a possible explanation for why the blocks required different amounts of force?

• The blocks all had different masses.

• The blacks all had the same mass but different sizes.

• The blocks had the same mass, but the force of gravity changed.

• Each student exerted the same force, but the friction was different.

Tags

NGSS.MS-PS2-2

When you coast down a hill on a scooter, you move faster and faster. If you continue moving onto a level surface, finally you will stop moving. Which of Newton's laws of motion explains why you stop?

• Newton's first law explains that when you reach the bottom of the hill, you run out of energy, so you stop moving.

• Newton's first law explains that gravity affects you when you move downhill, but not when you move on a level surface.

• Newton's second law explains that no force acts on your scooter on the level surface, so it stops moving.

• Newton's third law explains that friction between the tires and the ground is an unbalanced force that changes your motion.

Two race cars with the same mass started moving on a race track at the same time. One car reached the finish line of the track in 15 sec, and the other reached the finish line in 20 sec. Why did the cars take different amounts of time to reach the finish line?

• The force of gravity slowed one car but not the other car.

• The slower car did not experience any force, so it moved more slowly.

• The forces on one car were balanced and on the other car unbalanced.

• The engine of the faster car exerted more force than the engine of the other car.

Tags

NGSS.MS-PS2-2

Four forces are acting on the block shown below. If force F is applied to the block and it does not move, which statement is true?

• F and F(f) are equal

• F and F(g) are equal

• F(f) is greater than F

• F(g) is greater than F

Tags

NGSS.MS-PS2-2

According to Newton's laws of motion, which block will have the greatest motion?

• red

• blue

• green

• yellow

Tags

NGSS.MS-PS2-2

Why is it harder to overcome the inertia of a bowling ball than a basketball?

• because the bowling ball is larger

• because the bowling ball has a greater mass

• because the basketball has less momentum

• because the basketball has greater acceleration

Tags

NGSS.MS-PS2-2

What happens to an object that is acted upon by unbalanced forces?

• it stops moving

• it changes its motion

• it gets cold

• it gets hot

Tags

NGSS.MS-PS2-2

According to Newton's first law of motion, a moving object that is not acted on by an unbalanced force will

• remain in motion

• eventuall come to a stop

• transfer its energy to another object

• accelerate in the absence of friction