Three blocks of masses 1.0, 2.0, and 4.0 kilograms are connected by massless strings, one of which passes over a frictionless pulley of negligible mass, as shown above. Calculate each of the following.

Question

a. The acceleration of the 4 kilogram block

b. The tension in the string supporting the 4 kilogram block

c. The tension in the string connected to the l kilogram block
 
This is an atwood's machine were on the left side there is the 2.0 kg block and the 1.0 kg block

on the right side is the 4.0 kg block

can you tell me if my answers are correct

a 2.5 m/s^2

b 39 N

Thanks

Answer 1

Is C just 9.8 N

Answer 2

wait no 12 N

Answer 3

No. The net accelelerating force is (4-1-2)g

acceleration= netforce/total mass= g/(7)

How did you get double that in a)?
b)tension= 4(g-acceleration in a)
c) I am not certain where the 1 kg block is. If it is on the bottom of the left side, tension= 1g+accelearation in a)

Answer 4

acceleration = 1.4 m/s/s
tension of 4kg block is= 33.6 N
tension of 1kg block is= 11.2 N