One projectile after deviating from its path starts moving round the earth in a circular path of radius equal to nine times the radius of earth R. Its time period is

Options

A. `2pisqrt((R)/(g))`
B. `27xx2pisqrt((R)/(g))`
C. `pisqrt((R)/(g))`
D. `0.8xx10xx3pisqrt((R)/(g))`

Answer

B

Explanation

Net force towards the centre `impliesmomega^(2)(9R)=(GMm)/((9R)^(2))`
`impliesomega^(2)=(GM)/(729R^(3))impliesT=(2pi)/(omega)implies27xx2pisqrt((R)/(g))`