If the angular momentum of a rotating body about a fixed axis is increased by 10%. Its kinetic energy will be increased by

If the angular momentum of a rotating body about a fixed axis is incre

1.	If the angular momentum of a rotating body about a fixed axis is increased by 10%. Its kinetic energy will be increased by
Answer» 0.1 0.2 0.21 0.05 Solution :Kinetic energy of rotation , `K_(R) = (L^(2))/(2I)` For a given I (MOMENT of inertia of a body) , `K_(R) prop L^(2)` When the angular momentum of a body is increased by 10% i.e., `(L)/(10)` , its angular momentum will BECOME `L. = L + (L)/(10)= (11L)/(10)` `therefore (K._(R))/(K_(R)) = (L.^(2))/(L^(2)) = (((11L)/(10))^(2))/(L^(2)) = (121)/(100) , or K._(R) = (121)/(100) K_(R)` Percentage increase in the kinetic energy `(K._(R) - K_(R))/(K_(R)) xx 100 % = ((121)/(100) K_(R) - K_(R))/(K_(R)) xx 100 % = 21 %`