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

Explanation

Taking pointer and platform a system Man apply force F.
Hence, `F=T`
`4F-(M-m)g=(M+m)a`
`implies a=(4F-(M+m)g)/((M+m))`
`=(4F)/((M+m)-g`.