The time period of a satellite of earth is 5 hr. If the seperation between the earth and satellite is increased to 4 times the previous value the new time period will become ....  

Options

A. 10 hr
B. 80 hr
C. 40 hr
D. 20 hr

Answer

C

Explanation

`implies` According to `T^(2) alpha r^3`
`T_2^2/T_1^2=r_1^3/r_1^3`
`:. T_1^2/(25)=((4r)/r)^3`
`T_2^2 = 25 xx 64 `
`:. T_2 = 5xx 8 `
`:. T_2 = 40 hr `