1.Block B is placed upon block A, which is resting on the ground as shown in Figure 7.71. The coefficient of friction between all surfaces of contact is 0.25. Determine the force P required to move...

1.Block B is placed upon block A, which is resting on the ground as shown in Figure 7.71. The coefficient of friction between all surfaces of contact is 0.25. Determine the force P required to move block A.

2. A body of weight 50 N is at rest on an inclined surface (Fig 7.72). A force P is applied horizontally. If the coefficient of friction is 0.4, find the range of values of P over which the body will remain at rest.