Simple Physics Question?

Question

Refer to the Image ( http://img.photobucket.com/albums/v156/PNHTran88/01-3.jpg ). Block A has a mass of 2.00 kg and rests on a rough table and is connected to block B, which has a *** of 3.00 kg, after passing over an ideal pulley, as shown. Block B is released from rest. The coefficient of kinetic friction between block A and the table is 0.300. What is the acceleration of the masses?

Thanks a lot!!

Answer 1

These are most easily solved by looking at FBD of each component of the system. Since the pulley is ideal it can be ignored. The tension in the cord is T and positive is in the direction of motion
F=m*a

For mass onthe table
2*a=T-2*g*.3
for the hanging, just released mass
3*a=3*g-T

You have two equations and two unkowns..

Since we are solving for a, add the two equations together
5*a=g*(3-.6)
a=g*2.4/5
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