The New Childrens Encyclopedia

232

SCIENCE

Feel the force

Forces are at work all the time, pulling you down

to the ground, stopping you from slipping over, and

pushing you one way and then the next. Forces act

on everything, from the tiny nuclei inside atoms to

the planets and stars that make up the universe.

PULLING AND PUSHING

A force is a push or a pull. For example, your hand

applies a pulling or pushing force to open and close

a door. Forces act on all objects all of the time. They

make them move or change their speed or direction.

Your hand applies a pushing force

on a toy car to make it move.

HIDDEN

FORCES Usually

you must touch an

object to push or

pull on it. But some

forces act on things

without touching them.

For example, this magnet

pulls on these paper clips

with a magnetic force.

Action and reaction

When the boxer punches the

punching bag, his or her fist

applies a force to move it.

But the punching bag applies

an equal but opposite force

on the boxer’s fist to slow

it down.

A boxer’s fist lands a

powerful blow on a

punching bag.

(c) 2012 Dorling Kindersley. All Rights Reserved.(c) 2012 Dorling Kindersley. All Rights Reserved.