Force and Acceleration

Forces that are equal in size but opposite in direction are called unbalanced forces.

• True

• False

Answer explanation

Unbalanced forces are forces that are not equal in size and opposite in direction. Therefore, the statement is false.

Tags

NGSS.MS-PS2-1

If a net force acts on an object, the object may change speed, change direction or do neither.

• True

• False

Answer explanation

If a net force acts on an object, it can change speed, direction, or both. In this case, the correct choice is True.

Tags

NGSS.MS-PS2-2

Balanced forces acting on an object cause the object to accelerate.

• True

• False

Answer explanation

Balanced forces do not cause acceleration. Only unbalanced forces cause acceleration. Therefore, the statement is false.

Tags

NGSS.MS-PS2-2

According to Newton's second law of motion, a larger force acting on an object causes a greater __________ of that object.

Answer explanation

According to Newton's second law of motion, a larger force acting on an object causes a greater acceleration of that object.

Tags

NGSS.MS-PS2-2

When two forces act in the same direction on an object, the net force is found by __________ the forces.

Answer explanation

When two forces act in the same direction on an object, the net force is found by adding the forces.

Tags

NGSS.MS-PS2-2

Acceleration depends on which two factors?

• mass and position

• net force and mass

• mass and velocity

• position and net force

Answer explanation

Acceleration depends on net force and mass. These two factors determine how quickly an object's velocity changes.

Tags

NGSS.MS-PS2-2

Lizzie is pushing Alex on a scooter. Lizzie is pushing with 75 N of force to the left, and Alex is helping with 20 N to the left. What is the net force on the scooter?

• 95 N, to the right

• 95 N, to the left

• 55 N, to the right

• 55 N, to the left

Answer explanation

The net force on the scooter is 95 N to the left because Lizzie's force of 75 N to the left combined with Alex's force of 20 N to the left.

Tags

NGSS.MS-PS2-2

Friction always acts in a direction __________ to the direction of motion.

Answer explanation

Friction always acts in the opposite direction to the direction of motion.

Caleb is investigating the effect of friction on the motion of an object. He uses the following supplies for the investigation: a wooden block three ramps, each ramp is the same height and length but has a different surface (smooth wood, carpet, rough sandpaper) a stopwatch Caleb tests his hypothesis that the smooth wood ramp surface causes less friction than the carpet and that the carpet causes less friction than the rough sandpaper.

Describe a procedure using these supplies that Caleb may follow to test his hypothesis.

Tags

NGSS.MS-PS2-2

Explain the most likely reason Caleb uses the same wooden block for each test.

Tags

NGSS.MS-PS2-2

NGSS.MS-PS3-4