The acceleration due to gravity on the planet. A is 9 times the acceleration due to the gravity on planet B. A man Jumps to a height of 2m on the surface of A. What is the height of jump by the same person on the planet B ? 

Options

A. `2/3m`
B. `2/9m`
C. 18 m
D. 6 m

Answer

C

Explanation

`implies ` According to law of conservation of mechanical energy .
Kinetic energy of planet = Potential energy
For planet A :
`1/2 mv_A^2 = mg_(A) h_A `
For planet B:
`1/2 mv_B^2 = mg_Bh_B`
Suppose both planets having same orbital velocity
`v_A =v_B implies1/2 mv_A^2 =1/2 mv_B^2`
`:. g_A h_A = mg_B h_B`
`:. h_B = (g_A) /(g_B) h_A`
`= ((9g_B)/(g_B)) xx 2`
`= 9xx 2 = 18 m`