A spaceman in training is rotated in a seat at the end of a horizontal arm of length 5 m. If he can with stand acceleration upto 9 g, then what is the maximum number of revolution per second permissible? (Take, g =`10ms^(-2)`)

Explanation

In circular motion, necessary centripetal force to the man is provided by effective weight of man.
`therefore" "mxx9g=mromega^(2)=mrxx4pi^(2)n^(2)`
`rArr" "n=sqrt((9g)/(4pi^(2)r))rArrn=sqrt((9xx10)/(4xx(3.14)^(2)xx5))`
`=0.675"rev s"^(-1)` or hertz(Hz)