Physics Unit 3 Post Test

A car moves with an average speed of 45 miles/hour. How long does the car take to travel 90 miles?

• 2 mins
• 2 hours
• 45 mins
• 45 hours
• 90 mins

The graph describes the motion of an object. The object moves with _______ from A to B. It ________ from B to C. It moves with _________ from C to D.

• constant acceleration, slows down, constant acceleration
• constant velocity, remains stationary, constant velocity
• positive acceleration, speeds up, positive acceleration

Which segment of this graph shows a decreasing velocity?

• A to B
• B to C
• C to D
• D to E
• E to F

What is the primary force that helps suspension bridges use cables to hold their spans up?

• tension force
• resistance force
• normal force
• elastic force
• applied force

Akira is driving her car to work, but she’s stopped at a red light. When the light turns green, she presses the gas pedal and accelerates (speeds up) to move the car. Which of these statements is true the moment Gina presses the gas pedal? Assume the road is flat and level.

• The net force on the car is zero in the horizontal direction.
• The net force on the car is zero in the horizontal and the vertical directions.
• The net force on the car is greater than zero in the horizontal direction.
• The net force on the car is greater than zero in the vertical direction.
• The net force on the car is less than zero in the vertical direction.

Alejandro gently releases a ball at the top of a slope, but does not push the ball. The ball rolls down the slope. Which force caused the ball to move downhill?

• applied froce
• drag froce
• friction force
• gravitational force
• normal force

An object has one force acting on it. It is a 33-newton force pointing downward. To create a net force of zero on the object, which force must be applied to it?

• a 33-newton force pointing upward
• a 1-newton force pointing upward
• a 33-newton force pointing left
• a 0-newton force pointing downward
• a 1-newton force pointing right

Anne applies a force on a toy car and makes it move forward. What can be said about the forces acting on the toy car at the moment Anne applies the force? The forces acting on the toy car are ______________.

• restricted
• balanced
• equal
• unbalanced

A carmaker has designed a car that can reach a maximum acceleration of 12 meters/second2. The car’s mass is 1,515 kilograms. Assuming the same engine is used, what should the car’s mass be if the carmaker wants to reach an acceleration of 15 meters/second2? Use F = ma.

• 1,212 kg
• 1,335 kg
• 1,466 kg
• 1,515 kg
• 1,894 kg

Blake and Sandra are having a rummage sale. Blake drags 3 boxes a distance of 10 meters each. He exerts a force of 20 newtons on each box. Sandra drags 4 boxes a distance of 12 meters each. She exerts a force of 15 newtons on each box. Blake takes 2 minutes to complete his work. Sandra takes 4 minutes. Blake does _____ work than Sandra. Blake’s power is _______ than Sandra’s power. (Hint: Use W = Fd and (See Image))

• more, less
• less, more