How to Calculate Acceleration and Tension in a Pulley System

[iTheChosen1]

Pulley Question HELP!

Homework Statement

Blocks A and B are connected by a string passing over an essentially frictionless
pulley, When the blocks are in motion, Block A experiences
a force of kinetic friction of magnitude 5.7 N. If mA
5 2.7 kg and mB
5 3.7 kg,
calculate the magnitude of
(a) the acceleration of the blocks
(b) the tension in the string

Homework Equations

Fnet1 = Ft1 - Ff1
Fnet2 = Fg - Ft1

Ft1 = Ft2

The Attempt at a Solution

m1a - 5.7N = m2g - m2a
m1a - m2a = m2g + 5.7N

 

[BruceW]

You've recognised that the acceleration of both blocks must be the same. That's the most important step.
I think you may have mixed up your minus signs. It helps to draw the problem, then define for yourself which direction you will take to be positive.

 

[Rayquesto]

realize that the sum of all forces will always be mass times acceleration. therefor, Find each force affecting block A first and procede by making 2.7a equal to that and then do the same for block B. I'll give you a clue: the forces affecting block A are friction, Tension and gravitational forces. The forces affecting block B are only Tension and Gravitational force. add these up and make then = to ma ad replace m by their mass individually and you should get a good answer.