plz solve the query & give its xplanation

Asked by  | 7th Sep, 2008, 09:51: AM

Expert Answer:

i)If force is applied to the upper block the forces on this block are the applied force and the force of friction. The force of friction = (0.2)(2kg)(10) = 4N.

This is less than the applied force of 12N, so the net force on block A is 12- 4 = 8N;

It produces an acceleration in it given by F = ma or 8 = 2(a) or a = 4m/s^2.

The force on block B is only the force of friction which is 4N, so its acceleration will be 4N/4kg = 1m/s^2.

Note that here the blocks were placed on a smooth horizontal surface so there is no force due to the surface.

ii) When force is applied to the lower block, the two blocks will move together because the applied force is greater than the frictional force that 2kg block experiences.

F = (2 + 4) a

12 = 6a

a = 2m/s^2 of both the blocks.

 

Answered by  | 8th Dec, 2008, 11:14: AM

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