Answer to Question #74798 in Mechanics | Relativity for Callista

Question

A) A 6.0 kg mass sits atop a larger 9.0 kg mass which itself sits on a horizontal table top. A third, 3.0 kg mass hangs vertically just barely touching the right face of the large mass. A massless inflexible string connects the hanging mass to the top mass passing over a frictionless pulley (P). All horizontal surfaces have coefficients of static and kinetic friction of 0.80 and 0.40 respectively. All vertical surfaces are frictionless.

There is a little tap directly down on the hanging mass, just enough to cause this
block to slide. Assume this motion applies to parts 3, 4 and 5.

3) The 9.0 kg mass does not move. What is the acceleration of m2; tension now
in the string?
4) What is the magnitude of the net horizontal force on the pulley? What is the
magnitude of net force on the support rod (S) by the pulley?
5) What is the magnitude and direction of the total friction force on the large
mass, if any, at the interface between the table top and this mass?