GRAVITY

Gravity is an invisible force that pulls everything towards the earth. No matter how hard an object is thrown it starts to come back down to earth. This is an example of gravity at work. Gravity pulls everything down with the same force. It doesn't matter how heavy or how light the object is. It is the same for all objects.

slide
Seated on nylon mats, visitors breeze down a giant fiberglass slide in an amusement park. The slick mats make the ride faster because the mats slide on the fiberglass more easily than the visitors' clothing would.

Gravity also pulls matter together. The bigger an object is or the greater its mass, there will be more force of gravity. Gravity helps keep the planets orbiting around the sun.

skier

Pulled by gravity, a ski jumper races down a steep chute into the air. The skier's high speed carries him forward as he drops, making a long jump.

Gravity is what powers boxcars. These racers have just released their brakes and gravity is the force that is pulling them down the slope.
boxcar gravity

It also holds the hot gases in the sun. This is important because we get our heat, light, and energy from the sun. All box cars use gravity as their source of power.

by Chad, Melissa, and Matthew

Gravity
Friction
Bearings
Lubrication
Energy
Speed
Leverage
Center of
Gravity
Field Trip
Photos
Bibliography

Box Car Physics | Kapunahala