Page 110 - DK Children's Encyclopedia

Forces SEE ALSO

▸ ▸ Friction p.114
▸ ▸ Gravity p.125
A force is a push or a pull. Forces can start things moving, ▸ ▸ Magnets p.151
speed them up, or slow them down. Some forces work ▸ ▸ Measuring p.159
through touching. Others, such as gravity, work invisibly ▸ ▸ Solar system

and can affect objects a long way away. p.233
▸ ▸ Sun p.247

Pushing force Gravity
A pushing force makes things start to move A push away Gravity pulls objects down
and can also speed them up. Your hand applies from the hand. toward the Earth. It’s the
a pushing force when it moves a toy car. force that stops us from
floating off into space.

Gravity
pulls the
ball down.

Pulling force A pull toward Magnetism
A pulling force also makes the hand. Magnetism is a force that
things start to move. It moves pulls objects toward a
things forward from where magnet, or pushes them
the force is coming. away. Opposite magnetic
forces attract each other.

+ — + —

The magnets
pull together.
Friction
Balanced forces Engine power Friction is a force that
slows down movement.
pushes the
Pushes and pulls can act Friction car forward. It is created when two
pulls the car
in different directions at backward. surfaces touch.
the same time. If they When you sit still
are balanced, the object in a chair, the forces Muscles
moves at a steady on you are perfectly power the
speed, or is still. If one balanced. leg forward.
force is bigger, the object
gets faster or slower.
Gravity pulls
the car down.

Friction drags
108 the leg backward.

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