physics please help !
posted by emma on .
A box weighing 65.0 N rests on a table. A rope tied to the box runs vertically upward over a pulley and a weight is hung from the other end.
Part a) Determine the force that the table exerts on the box if the weight hanging on the other side of the pulley weighs 24.0 N .
Part b) Determine the force that the table exerts on the box if the weight hanging on the other side of the pulley weighs 43.0 N .
part c)Determine the force that the table exerts on the box if the weight hanging on the other side of the pulley weighs 82.0 N .

m•g = 65 N, m1•g =24 N, m2•g =23 N, m3•g =82 N
Tthe force that the table exerts on the box is the normal reaction
(a) N =m•g –T1 = m•g –m1•g =
= 65 – 24 = 41 N,
(b) N =m•g –T2 = m•g –m2•g =
= 65 – 43 = 22 N,
(c) N =0.
The box is moving at the acceleration
a = g•(m3m)/(m3+m) 
this is 13