2006-10-18 14:12:29 · 6 answers · asked by p 1 in Science & Mathematics ➔ Physics
friction always acts in the direction opposite of the motion of the system, so it always takes energy away from the system
2006-10-18 14:14:11 · answer #1 · answered by suprasteve 3 · 1⤊ 0⤋
Friction is a force that keeps the object from moving into ANY direction linear to the surface of the 2 touching objects. It does not 'push' the object in any direction at all. If it were pushing the object, you'd see table or chair or anything moving around like crazy :)
If you make one object move while it's touching another object, you'd feel as if there's another force that 'push' back. The real explanation is that it doesn't push you back, it just prevent you from moving the object.
For example, if you put a large table on the floor, it'd stand still, right? When you push it, you'll need an amount of energy to make it start moving. Try putting the very same table on ice rink (hockey rink), and you could move it with ease. That's the concept of Friction force. The surface of the floor has a bigger friction coeficient compared to the surface of ice. The mass of the table remains the same of course.
The formula is something like this (remembered it vaguely):
Friction force = friction coeficient x mass of the moving object.
The friction coeficient remains the same for a particular object as long as the surface isn't altered in any way, namely putting oil on top, or grind it to a smooth surface. Friction coeficient usually around 0 (0.1, 0.3, etc). The mass of the object also contributes to the force. Pushing a chair and a large table across the very same floor requires different amount of energy.
Heat is the byproduct of the action. As you know, force cannot be diminished. Force can however, change form. In this case, friction force change its form to heat force. This is what happened to wooden matches. The surface is very coarse and flammable. The friction force change form to heat force, and heat force fires up the match.
Back to your question, the effect of friction force on a motion of an object, is decelarate it to eventually comes to a stop. So when an object is moving, the touching surface is preventing the object to move, not 'pushing' it back.
2006-10-18 20:38:46 · answer #2 · answered by Marcus 2 · 0⤊ 0⤋
Friction causes heat and slows down motion. It can also prevent motion if pressured.
2006-10-18 14:15:05 · answer #3 · answered by Anonymous · 1⤊ 0⤋
Friction slows down objects and keeps them from slipping away.
2006-10-18 14:19:35 · answer #4 · answered by Anonymous · 0⤊ 0⤋
friction slows the motion.
(Gimme the 10 points, buster)
2006-10-18 14:15:33 · answer #5 · answered by davidosterberg1 6 · 0⤊ 0⤋
JAREAD
Answered the question just as I would. Excellent answer. Give him credit for that.
2006-10-18 14:24:01 · answer #6 · answered by Anonymous · 0⤊ 0⤋