A body of mass 1 kg is thrown upwards with a velocity 20 ms^(-1) .It momentarily come to rest after attaining a height of 18 m . How much energy is lost due to air friction (g = 10 m//s^(-2))

A body of mass 1 kg is thrown upwards with a velocity 20 ms^(-1) .It m

1.	A body of mass 1 kg is thrown upwards with a velocity 20 ms^(-1) .It momentarily come to rest after attaining a height of 18 m . How much energy is lost due to air friction (g = 10 m//s^(-2))
Answer» 30 J 40 J 10 J 20 J SOLUTION :When a body thrown UPWARDS , its kinetic energy converted into POTENTIAL energy and energy lost due to friction is equal to th difference between kinetic and potential energy . ` :. " Energy lost "= K - V ` ` = 1/2 mv^(2) -mgh` ` = 1/2 xx 1xx 400 -1 xx 10 xx 18` ` = 200 - 180 = 20 J `