How Much Weight Must Block C Have to Prevent Block A from Sliding?

[djester555]

blocks A and B have weights of 45 N and 25 N, respectively.



block A is sitting on a table and block B is attached to block A by a piece of string on a frictionless pulley and block B is hanging off the table. also block C is on top of block A



Figure 6-48
(a) Determine the minimum weight of block C to keep A from sliding if µstat between A and the table is 0.20.

(b) Block C suddenly is lifted off A. What is the acceleration of block A if µkin between A and the table is 0.15?
2 m/s2




A)
block a = 45n
block b = 25n
block c = 45 -25
block C = 20N i don't think this is right

B) can't solve without part A

 

[rl.bhat]

Find out the forces acting on A and C. Similarly find out the force acting on B. Find the acceleration of the system. Find the condition for the equilibrium.