Force and Motion Released Items

A wagon is pushed in a straight line. How would an increase in friction on the wagon wheels affect the wagon?

• It would cause the wagon to move faster

• It would cause the wagon to change mass.

• It would cause the wagon to change direction

• It would cause the wagon to slow down

A runner measured the time it took him to run 5 km. What can he calculate from the distance and time measurements?

• direction

• mass

• speed

• force

Which best explains why a bicycle slows down when its brakes are applied?

• The brakes heat the rubber on the bicycle tires

• The brakes add energy to the bicycle

• The brakes increase the force of gravity on the bicycle

• The brakes cause frictional forces on the wheels of the bicycle

If a car is moving backward along a road, can its speed be measured?

• Yes, it can, because the car does not have friction acting on it.

• Yes, it can, because the car travels a distance in a certain amount of time.

• No, it cannot, because speed can only be measured if the car is moving forward.

• No, it cannot, because the distance traveled backward by a car cannot be measured.

Scientists discover an asteroid that is moving through space. What information is needed to determine the average speed of the asteroid?

• the mass and size of the asteroid

• the distance the asteroid is from Earth

• the direction the asteroid is moving and its distance from Earth

• how far the asteroid has moved in 24 hours

What causes a wagon to speed up when going down a hill?

• gravity

• friction

• air pressure

• mass

A bowling ball moves across a flat surface at 7 feet per second. If a student is asked to calculate the total distance traveled by the ball, what other information does the student need to know?

• amount of friction between the ball and the surface

• amount of force applied to the ball

• total time the ball rolled

• mass of the ball