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Format
Mar29-04, 10:28 PM
Test tomorrow an im sure somthing like this will be on it. What is needed to find out the work done upon a 50.0-kg cylinder that is being pushed up a 3-m high, 6-m long (hypotonuse) ramp?

cookiemonster
Mar29-04, 10:36 PM
The mass of whatever's being pushed, the coefficient of friction between whatever's being pushed and the ramp, and any two of the following: the length of the ramp, the height of the ramp, the hypotenuse of the ramp, the angle of elevation of the ramp.

cookiemonster

Format
Mar29-04, 10:44 PM
Is this correct? :

Sin^-1(3/6) = 30°

50.0 x 9.8 = 490-N

Sin30(490) = 245-N

W= 245 x 6 = 1476-J

Oh and theres no friction needed.

cookiemonster
Mar29-04, 11:28 PM
Ah... Looks right to me.

cookiemonster

Chen
Mar30-04, 03:33 AM
If there is no friction, you can just use the potential energy of the object. You know that at the bottom of the ramp, its potential energy is zero. You also know that at the top of hte ramp, its potential energy is mgh. You also know that the work done by non-conservative forces is equal to the change in mechanical energy of the object. Therefore:
W = \Delta E_M = \Delta E_p = mgh = 50kg * 9.8\frac{m}{s^2} * 3m = 1470J