The escape speed of a body on the earth's surface is 11.2 km `s^(-1)`. A body is projected with thrice of this speed. The speed of the body when it escapes the gravitational pull of earth is

Answer

`31.68 xx 10^(3) ms^(-1)`

Explanation

`v_(1) = 3v_(1) `. V is the escape velocity . `( 1//2) mv_(1)^(2) + ( - ( GMm)/( r )) = ( 1//2) mv_(2)^(2) + 0, v_(2) = sqrt( 8 ) xxv = sqrt( 8) xx 11.2 xx 10^(3) = 31.68 xx 10^(3) ms^(-1)`