a 20kg object rest on horizontal surface. A horizontal string is attached to the object. the string is passed over a friction less, mass less pulley so that is hangs vertically. A 5kg mass is hung from the vertical string. what is the acceleration of each object and the tension in the string?

Solution:

The acceleration of both is a, the tension is T

So

T = Ma

mg-T = ma

So

a = mg/(M+m) = 5*9.8/(20+5) = 1.96 m/s2

T = 20*1.96 = 39.2 N

So the acceleration of both is 1.96 m/s2, the tension is T=39.2N