# Block A supports a pipe column and rests as shown on wedge B.Knowing that the coefficient of static friction at all surfaces of contact is 0.25 and that θ = 45°, determine the smallest force P required to raise block A.

Question-AnswerCategory: Engineering MechanicsBlock A supports a pipe column and rests as shown on wedge B.Knowing that the coefficient of static friction at all surfaces of contact is 0.25 and that θ = 45°, determine the smallest force P required to raise block A.

Block A supports a pipe column and rests as shown on wedge B.Knowing that the coefficient of static friction at all surfaces of contact is 0.25 and that θ = 45°, determine the smallest force P required to raise block A. Step: 1

Calculate the friction angle by using the following relation: Substitute 0.25 for . Step: 2

Draw the free body diagram of the block A. Here, are the reaction forces on block A.

Step: 3

Draw the force triangle for block A. Step: 4

Apply the law of sine and solve. Substitute for and for .    Step: 5

Draw the free body diagram of wedge B. Step: 6

Draw the force triangle for block B. Step: 7

Calculate the smallest force P.
Apply the law of sines and solve. Substitute for and for .  Therefore, the smallest force required to raise block A is .