8th Grade Science - Force and Acceleration

A force of 80N acts upon a 250 kg refrigerator. What equation shows the correct

calculation to find the acceleration of the object? F= m x a

• a= 80 N x 250 kg8

• a = 80 N ÷ 250 kg

• a = 250 kg ÷ 80N

• a = 250kg x 80N

What is one difference between acceleration and velocity?

• Acceleration is the change in speed whereas velocity is the change in speed or

  direction

• acceleration is the change in velocity over a period of time whereas velocity is

  distance covered over a period of time

• Acceleration and velocity are the same; there are no differences.

Bobby is slowing down on their skateboard. They start at 12 m/s and slows to 3 m/s over a

time of 6 seconds. What is their initial velocity?

• 9 m/s

• 3 m/s

• 6 m/s

• 12 m/s

Acceleration depends on which two factors?

• mass and position

• position and net force

• mass and velocity

• net force and mass

Mikey is pushing Tommy on a scooter. Mikey is pushing with 80 N of force to the left, and

Tommy is helping with 30 N to the left. What is the net force on the scooter?

• 110 N to the right

• 110 N to the left

• 50 N to the left

• 50 N to the right

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

• balanced

• unbalanced

• Net

• acceleration

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

greater __ of that object. F = m x a

• meters

• acceleration

• meters

• mass

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

• balanced

• unbalanced

• Net force of zero

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

forces.

• Multiplying

• Dividing

• Adding

• Subtracting

Friction is a force that always acts in a direction __ to the direction of motion.

• parallel

• opposite

• equal to

• similar