Question

If the angular momentum of a body increases by 50%, then its kinetic energy of rotation increases by ______ (M.I. remains constant)

विकल्प

• 50%

• 100%

• 125%

• 200%

Answer 1

125%

Explanation:

K = `1/2"I"ω^2 = "L"^2/(2"I")`

∴ `"K"_"f"/"K"_"i" = ("L"_"f"/"L"_"i")^2 = (150/100)^2 = 9/4`

∴ `("K"_"f" - "K"_"i")/"K"_"i" xx 100 = ("K"_"f"/"K"_"i" - 1) xx 100`

= `(9/4 - 1) xx 100`

= `500/4 = 125%`.