IIT JEE , AIEEE Forum - Physics , Mechanics

karthik2007

I think he is offline, so I'll explain it for you:

See, the acceleration of the system is gsin37.

Now, the forces acting on the block of mass m are:

1) mgsin37 down the incline
2) fcos37 (f - force due to friction) down the incline) [ As friction opposes relative slipping, and the mass m has a tendency to move backward, so f acts in the forward dirn]
3) Nsin37, up the incline

Now, the acceleration of the system is gsin37, so the force acting on the block is mgsin37

So, we have:

mgsin37 + kNcos37 - Nsin37 = mgsin37

or k = tan37= 3/4 = 0.75.

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