Question

A block of mass 1kg is connected by a light string passing over two smooth pulleys placed on a smooth horizontal surface as shown. Another bolck of 1kg is connected to the other end of the string then acceleration of the system and tension in the string are

(A) 5ms^-2, 5N 

(B) 1ms^-2, 1N 

(C) 1ms^-2, 5N 

(D) 5ms^-2, 10N

Answer 1

Let T N be the tension on the string  and a m/s^2 be the acceleration of the system.

Now considering the forces on the 1kg block lying on the frictionless table we can write

T = 1×a .........(1)

Again considering the forces on hanging 1kg block we can write

1×10 - T=1×a.......(2),taking g=10m/s^2

Adding (1) and ( 2) we get

2a=10 => a=5m/s^2

So T = 1×5=5N

Answer 2

(A) 5ms^-2 , 5N