Force and Pressure, Friction

1.During dry weather, while combing hair, sometimes we experience hair flying apart. The force responsible for this is

• the force of gravity.

• electrostatic force.

• force of friction.

• magnetic force.

Determine the pressure when the force of 200N acts on area of 20m2 .

• 200Pa

• 1/10 Pa

• 0.002Pa

• 10Pa

A student investigated the relationship between the weight of a block and the friction between it and the surface. As he added weights to the block, he found that the force needed to move the block

• increase

• stays the same

• Decreases

• No change

A boy is cycling along a road. When he applies the brakes, which one of the following forces occurs between the brake pads and the wheels.

• Gravity

• Magnetic

• Friction

• Stretching

The force of friction that comes into play when one body rolls over another surface, is

• sliding friction

• limiting friction

• rolling friction

• static friction

Why sportsmen use shoes with spikes? Choose the correct statement.

• It helps to increase friction on the ground.

• In order to avoid getting slip.

• makes a proper grip on the ground.

• all of the above.

A car is moving on a rough road. If the road becomes smoother, what happens to the frictional force acting on the car?

• Increases

• Decreases

• Stays the same

• Becomes zero

What type of friction acts when a book is pushed across a table but does not move?

• Static friction

• Kinetic friction

• Rolling friction

• Limiting friction

If a person stands still on a flat surface, which force is primarily acting against gravity?

• Normal force

• Frictional force

• Magnetic force

• Electrostatic force

If a force of 150N is applied on an area of 30m2, what is the resulting pressure?

• 5Pa

• 0.5Pa

• 150Pa

• 4.5Pa