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Doc Al
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#15
May11-04, 07:56 AM
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I think you've got it (close enough).
Quote Quote by indebluez
okye i finally get it:) theres a net force actiing on the ball....this net force on the ball is the force that provides the acceleration upwards...
Right. During the collision, the net force on the ball is upwards.
the net force on the ball, is the force of the table on the ball...right?
"net" force means the (vector) sum of all the forces. On the ball we have two forces: its weight (acting down) plus the large force of the table on the ball (pushing up). The sum of those two forces gives a net force upwards.

It's the net force that determines what happens to the body--how it will accelerate. You can have high forces applied to a body and still have a zero net force. For example: step on a rubber ball, squashing it against the ground. There are several forces on the ball: your foot exerts a high force, the weight of the ball exerts a force, and the ground pushes up with a large force. But the net force is zero: they all cancel out.
theres an equal n opp force on the table exerted by the ball...hence theres a force on the table as well.....
Right. When the table exerts a force on the ball, the ball exerts an equal force on the table. That's Newton's 3rd law. (Note: this applies to the individual forces between bodies, not the net force.)