Question

The 25-kg block is attached to link AB and rests on a moving belt. Knowing that μs= 0.30 and μk= 0.25 and neglecting the weight of the link, determine the magnitude of the horizontal force P that should be applied to the belt to maintain its motion (a) to the left, (b) to the right.

Answer 1

To maintain the motion of the 25-kg block on the moving belt, the magnitude of the horizontal force P can be determined using the static and kinetic friction coefficients. For motion to the left, P = 73.5 N, and for motion to the right, P = 61.25 N.

Step-by-step explanation:

To determine the magnitude of the horizontal force P needed to maintain the motion of the 25-kg block on the moving belt, we need to consider the static and kinetic friction coefficients.

(a) To maintain the motion of the block to the left, the static friction coefficient is relevant. Using the equation of static friction, the magnitude of P can be found by multiplying the static friction coefficient (μs) by the normal force:

P = μs * N = 0.30 * (25 kg * 9.8 m/s^2) = 73.5 N

(b) To maintain the motion of the block to the right, the kinetic friction coefficient is relevant. Using the equation of kinetic friction, the magnitude of P can be found by multiplying the kinetic friction coefficient (μk) by the normal force:

P = μk * N = 0.25 * (25 kg * 9.8 m/s^2) = 61.25 N