In the arrangement shown in the figure the mass `M` is very heavy compared to `m (M gt gt m)`. The tension `T` in the string suspende from the ceiling is

Options

A. `4 mg`
B. `2 mg`
C. zero
D. None of these

Answer

B

Explanation

`a = ("Net pulling force")/("Total mass") = ((M - m)g)/((M + m))` …(i)
Since `M gt gt m`
`:. M - m ~~ M + m = M`
Subtituting in Eq. (i),we have
`a = g`
`FBD` of `m` `T - mg = ma = mg`
`:.T = 2 mg`