A mass of mass 60 kg hangs himself from a massless spring balance. Which itself suspneded from an ideal string-pulley system as shown in the figure. The stirng AB can bear maximum 900 N. Choose correct statement.

Options

A. The man is never ever able to read his correct weight in the spring balance.
B. If man is able to manage himself at rest, the spring balance reads his true weight.
C. The maximum magnitude of accelerationman can manage is 12.5 `m//s^(2)` while moving upward.
D. When man moves downward with acceleration `5m//s^(2)` the spring balance will read 40 kg.

Answer

C

Explanation

`2T-Mg+T=MaimpliesMg-3T=Maimplies3T=M(g-a)` ..(i)
2T=kx
`T=(M(g+a))/(3)`
Reading of spring balance `=(kx)/(g)=(2T)/(g)={{:((2M(g+a))/(3g),("When moving upward")),((2M(g-a))/(3g),("When moving downward")):}`