A rubber ball is dropped from a height of 5 m on a planet where the acceleration due to gravity is not known. On bouncing it rises to 1.8 m. The ball loses its velocity on bouncing by a factor of:

Options

A. `(16)/(25)`
B. `(2)/(5)`
C. `(3)/(5)`
D. `(9)/(2)`

Answer

b

Explanation

Let `g_(p)`=value of .g. at the planet
Then `(v_2)/(v_1)=sqrt((2gph2)/(2gph1))=sqrt((1.8)/(5))=sqrt((9)/(25))=(3)/(5)`
Now `(v_1-v_2)/(v_1)=1-(v_2)/(v_1)=1-sqrt((18)/(50))=13//5=2//5`