A brick that weighs 23 kg is laying on a table. The brick is retained. From the brick, a thread is connected via a castor to a weight with the mass of 19 kg.

With how much force do the thread effect the hanging weight if you release the brick. Coefficient of friction between the brick and the surface is 0,17. Don't mind the other frictionlosses.

1 answer

weight of brick = m g = 23 * 9.81=226 N
friction resistance maximum = 226*.17= 38.4 N

on brick:
T - 38.4 = 23 a so a= (T-38.4)/23

on weight
19*9.81 - T = 19 a so a = (186-T)/19

23(186-T) = 19(T-38.4)
solve for T, the tension in the thread.