A conveyer belt is to be selected among the four options available for a manufacturer.The selection criterion is that the material of the belt offer the required coefficient of friction so that the mass of 10 kg that is carried by the conveyer of radius 3m, that travels at 0.5 m/s first begins to slip off at an angle of 25o.
1) ms = 0.51.
2) ms = 0.23.
3) ms = 0.12.
4) ms = 0.42

Since the belt moves with constant speed,at = 0.
Applying the equations of motion-

10 sin 25 - Ff = 10(0) --------------------------(1)
10 cos 25 - N = 10(0.5)2/3 -------------(2)

Solving equation 1 gives-
Ff = 4.226 N.
Solving the second equation gives-
N = 8.2294 N.

Placing the value of N in Ff-
Ff = msN
ms = 0.51