Question 20. For increasing the angular velocity of an object by 10%, the kinetic energy has to be increased by
Correct option is D) Let initial energy be K and angular velocity be w after change become K ′ andw ′ ω ′ =1.1ω(given) K= 2 1 Iω 2 K ′ = 2 1 I(ω ′ ) 2 = 2 1 I(1.1ω) 2 =1.21( 2 1 Iω 2 ) =1.21K Therefore kinetic energy should be increased by 21%
