grade 4 , con 4 , lesson 4

All of the following examples can move by a pushing force, except

• a ball.

• a swing.

• tug-of-war rope.

• a car.

To stop a moving object we can apply a......... against it.

• pushing force

• gravity force

• sound energy

• light energy

Samir pushed his toy car that moved forward, to stop it he should.........

• push it in the same moving direction.

• pull it with a small force in the same moving direction.

• pull it with a large force in the same moving direction.

• push it in a direction opposite to its moving direction.

The work done is equal to the amount of........... transferred by a force that is used to move an object.

• energy

• friction

• pushing

• gravity

Put (✔) or (x): If a person moves a table through a distance, there is a work done.

• True

• False

Put (✔) or (x): Lifting a book upward needs more energy than pushing a truck.

• True

• False

Put (✔) or (x): If you try to open a door but you cannot open it, this means that work is done.

• True

• False

Put (✔) or (x): Hitting a tennis ball needs a pulling force.

• True

• False