A man of mass`m` stands on a plateform of equal mass `m` and pulls himself by two rops passing over pulleys as shown in figure.If he pulls each rop with a force equal to half his weight ,his upwards acceleration would be

Options

A. `(g)/(2)`
B. `(g)/(4)`
C. `g`
D. zero

Answer

D

Explanation

Total upward force `= 4 ((m g)/(2)) = 2 m g`

Total downward force`= (m + m) g = 2 m g
`:.` Net force`= 0`
`F = (mg)/(2)`