Why do the tires on your bike roll better when they're all pumped up than when they're soft? And why do your roller blades go better on smooth pavement than on a sandy road? The answer is friction...the big rub! The force that slows you down and gets you going; without friction, you'd be slip slidin' away!
Find yourself a big open room. You may have to move some furniture around. Lay your books down on the floor at one end of the room and rest one end of the board on top of it. The board should now look like a ramp.
The ground rules are as follows:
Okay, here's the challenge question: Which do you think will roll farther down the ramp, the can of clear soup, the can of creamed soup or the can of chunky soup? (Maybe they'll all go the same distance, after all, they're the same size and shape!)
General Science Sites
Science and Technology for Children Curriculum
The Natural History Museum (London) Edison National Historic Site Endangered Species Program
Edison National Historic Site
Endangered Species Program
Potential Energy: Energy that can be used later. (When you're at the top of a hill, you have potential energy.)
Kinetic Energy: The energy of an object in motion. (Roll down the hill, and you've turned your potential energy into kinetic energy.)
Gravity: The force that pulls things toward the Earth.
Friction: When one thing slides against another, friction slows down the motion.
Drag: Friction between a moving object and the air around it. Drag also slows things down.
Momentum: The "oomph" of a moving object. The more momentum something has, the longer it can keep moving and the harder it is to stop.