Question

Two bodies A and B hanging in air are tied to two ends of a string which passes over a frictionless pulley.The masses of string and pulley are negligible.Two masses are 2kg and 3kg respectively. Then mass 2kg moves up under a net force equal to​

Answer 1

30−T=3a

T−20=2a

T=24

Hence Force =24−20

Force =4 N

Answer 2

Answer:

The mass of 2kg moves up under a net force equal to 4N.

Explanation:

The tension of the bodies in the pulley mass system is given as,

$T=\frac{2m_1m_2}{m_1+m_2} g$       (1)

Where,

T=tension on the bodies

m₁,m₂=respective masses of the body

g=acceleration due to gravity=10m/s²

From the question we have,

m₁=2kg

m₂=3kg

By substituting the required values in equation (1) we get;

$T=\frac{2\times 2\times 3}{2+3} \times 10$

$T=\frac{12}{5} \times 10$

$T=24N$        (2)

The net force acting on mass "2kg" is given as,

$F=T-W$      (3)

F=net force acting on the mass of 2kg

T=tension in the pulley mass system

W=weight of the mass 2kg=2×10=20N

By substituting all the required values in equation (3) we get;

$F=24-20$

$F=4N$

Hence, the mass of 2kg moves up under a net force equal to 4N.