Stored Energy?


Posted by Robert on Apr 15, 2004 at 15:04
(63.190.33.155)

They taught us in physics 1 that "work" is force exerted over distance and that force requires energy.

We were also taught that energy cannot be created nor destroyed, so here's my question:

Imagine a plastic ramp on your desk, slightly inclined so that when you release a ball bearing at the top of the ramp, it rolls to the bottom.

Now place a "permanent" magnet under the ramp and slightly to the right of the ramp's centerline.

When you release ball bearings from the top of the ramp from a point slightly left of the centerline, each will be pulled to the right as it passes the magnet.

Is it correct to assume that the magnet is doing "work" to the extent that it's exerting a force on the ball bearings over the small distance between their "straight ahead" and "deflected" paths?

If that's true, then will the magnet lose its ability to attract the ball bearings, i.e., lose its magnetism, when the energy used to deflect X thousands of ball bearings equals the amount of energy it took to magnetize the magnet in the first place?

Or will the magnet continue to attract the ball bearings essentially "forever"? In which case, the question is, where is the energy coming from that allows the magnet to continue to exert a force through a distance, that is, to work?

Follow Ups:


Post a Followup

Name:
E-Mail:

Subject:
Comments:

[ Forum ] [ New Message ]