A contact force is a force that

• acts between objects that are not touching

• pulls all objects toward the center of the earth

• acts only when one object touches another object

A leaf falling from a tree is an example of.

• a contact force

• a noncontact force

• magnetism

Position is the

• place where an object is

• measurement of how fast an object moves

• way that an object faces

Force, motion, and speed work together because

• of chance

• God designed them to work together

• people make them work together

Balanced forces are acting on an object.

• two forces that are unequal in strength

• two forces that are equal in strength and opposite in direction

• two forces that are unequal in strength and in the same direction

What pattern of motion do you observe when you use a light switch?

• a round-and-round motion

• a zigzag motion

• an up-and-down motion

Walter is putting up a flag on a windy day. What pattern of motion can you predict for the flag?

• a back-and-forth motion

• revolution

• a round-and-round motion

Why can some motions not be predicted?

• because the motion has different forces

• because there is no pattern of motion

• because the motion has unbalanced forces

The cat watches as Peggy adds eggs to the cake batter in the mixer. What living thing is doing the work?

• a machine

• a person

• an animal

Which one is an example of using a force to do work better?

• Jacob is carrying mulch in his hands from the driveway to the garden.

• Jacob is dragging the bag of mulch across the lawn to the garden.

• Jacob is moving the mulch from the driveway to the garden with a wheelbarrow.