Force and Friction

Which diagram represents balanced forces?

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Which pair of forces will cause the object to move to the right?

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How much an objects motion changes when force is applied to it depends on the strength of the force and the object's

• size

• mass

• volume

• velocity

Why is force a vector?

• It causes objects to move

• It has size and direction

• It can be measured

• Yoda made it so

One Newton is defined as the amount of force that causes

• a weight of 1 pound to reach a speed of 1 m/s

• a mass of 1 kilogram to accelerate at 1 m/s²

• an object to increase its velocity to 1 m/s²

• any stationary object to start moving

What is the net force acting on the object pictured below?

• 50 N right

• 30 N right

• 30 N left

• 50 N left

If two forces act on an object in the same direction

• the net force is greater than either of the two forces

• the net force is less than either of the two forces

• the net force will always be balanced

• none of these are true

Which type of friction do you use when you put on the brakes to stop a bike?

• static friction

• stopping friction

• rolling friction

• sliding friction

Why does engine oil help prevent an engine from overheating?

• It causes chemical reactions that absorb energy

• It reduces friction between moving parts

• It has a higher melting point than metal

• It makes the engine run more slowly

Friction is greater when surfaces are

• rougher

• smoother

• smaller

• taller