S8 - Review topic Energy

What unit do scientists use to measure power?

• Joule

• Watt

• Kelvin

• Newton

If three force are pulling on an object with 4 Newtons to the right, and one Newton up, and 4 Newtons to the left. What is the net force?

• 1N

• 5N

• 8N

• 9N

What is Newton's third law?

• law of gravity

• law of force and acceleration

• law of action-reaction

• law of inertia

A train that is accelerating at 5 m/s2 down the tracks and crashes into a car. If the train weighs 20,000 kg, how much force does the car experience?

• 200,000N

• 300,000N

• 400,000N

• 100,000N

What is the mass of an object that requires a force of 90 N to accelerate at a rate of 2.6 m/s2

• 44.6 kg

• 54.6 kg

• 34.6 kg

• 89.6 kg

When a bus starts suddenly, the passengers are pushed back. This is an example of which of the following?

• Newton's first law

• Newton's seocond law

• Newton's third law

• None

What is the speed of a bobsled whose distance-time graph indicates that it traveled 100 m in 25 seconds?

• 4 m/s

• 250 m/s

• 0.25 mph

• 100 m/s

Friction is a force that acts in a direction the _______ of the motion.

• opposite

• same

• different

• equal

Sam stands on one side of the filing cabinet and pushes with a force of 60 N. If Nathan wants

to help Jennifer demonstrate balanced forces, what does he need to do?

• Stand on the same side of the cabinet and push with a force of 60 N in the same direction as Sam.

• Stand on the opposite side of the cabinet and push with a force of 60 N toward Sam.

• Stand on the opposite side of the cabinet and push with a force of 120 N toward Sam

• Cause the cabinet to move.

If a car is travelling on the highway at a constant velocity, the force that pushes the car forward must be

• greater than the weight of the car.

• greater than the force of friction exerted upon the car.

• equal to the weight of the car.

• equal to the force of friction exerted upon the car.