Gravity & Friction Review

Which action results in increased friction?

• adding wax to skiis

• applying sand to a road

• polishing a metal surface

• applying grease to a bicycle chain

A ball is pushed off the edge of a table to the floor. The ball moves faster and faster as it comes down. What factor causes the motion of the ball to change as it falls to the floor?

• the force of gravity

• the height of the table

• the mass of the ball

• the force applied to the ball from the push

Mollie kicks the soccer ball to score a goal. What force will cause the ball to stop rolling across the field?

• electricity

• friction

• gravity

• magnetism

A student releases a baseball and a bowling ball from the same height at the same exact time. What will happen?

• The baseball will hit the ground first because there is less friction acting on the baseball.

• The bowling ball will hit the ground first because it has more mass.

• The bowling ball will hit the ground first because gravity is pulling harder on the bowling ball.

• The balls will hit the ground at the same time because gravity accelerates the balls at the same rate.

Petter rides his bike down a ramp and applies the brakes to slow down. What force acts between the wheels of the bike and the ramp that causes the bike to slow down?

• acceleration

• friction

• gravity

• mass

Which statement best describes what happens to a golf ball after it is hit into the air?

• The mass of the golf ball increases, causing the golf ball to fall back to the ground.

• The force of friction on the golf ball decreases, causing the golf ball to fall back to the ground.

• The force of gravity pulls on the golf ball, causing the golf ball to fall back to the ground.

• The shape of the golf ball changes, causing the golf ball to fall back to the ground.

Jocelyn pushes her toy bus on a smooth tile. She then pushes it across a rough tile. How and why will the motion of the bus change?

• The bus would move faster on a smooth surface than on a rough surface because rough surfaces create more friction.

• The bus would move faster on a smooth surface than on a rough surface because rough surfaces create less friction.

• The bus would move faster on a rough surface than on a smooth surface because rough surfaces create more friction.

• The bus would move faster on a rough surface than on a smooth surface because rough surfaces create less friction.

A car spins out of control due to icy road conditions. What causes the car to spin out of control?

• The ice increases friction between the tires and the road.

• The ice causes the tires to move slower.

• The ice freezes the surface of the tires.

• The ice reduces friction between the tires and road.