PLENARY: IDENTIFYING FORCES

A book is at rest on a table. Check all the forces that act on it.

• gravity

• normal force

• applied force

• friction

A small child is pulling a wagon to the left, at a constant speed. Check all the forces that are acting on the wagon.

• Gravity

• Normal Force

• Applied Force

• Friction

The football is flying upward and to the right. Check all the forces that are acting on it.

• Gravity

• Normal

• Applied

• Friction

The hockey puck is sliding across perfectly smooth ice, at a constant speed. Check all the forces that are acting on it.

• Gravity

• Normal Force

• Applied Force

• Friction

Mickey is climbing a rope. What forces are acting on him?

• Gravity

• Normal Force

• Applied Force

• Tension

TRUE or FALSE

Friction force always goes in the same direction as the motion of an object.

• True

• False

TRUE or FALSE

Normal force is always perpendicular to the surface at which an object is resting.

• True

• False

What makes a rolling ball stop moving?

• Gravity
• Friction
• A balanced force
• An applied force

Look at the illustration below of a block sitting on a table-top. The magnified view illustrates a force that exists between the two objects.

Which type of force is demonstrated in the magnified view?

• magnetic force

• drag force

• gravitational force

• frictional force

Units used to measure force are

• pounds

• Newtons

• Isaacs

• meters