A particle of mass m = 5 units is moving with a uniform speed v = `3sqrt(2)` m in the XOY plane along the line Y = X + 4. The magnitude of the angular momentum about origin is :

Options

A. zero
B. 60 unit
C. 7.5 unit
D. `40sqrt(2)` unit

Answer

B

Explanation

Angular momentum about origin

`abs(vec(L))=abs(vec(r) times mvec(v))`
`" "=(4cos45^(@)) times (5) times 3sqrt(2)`
`" "4/sqrt(2) times 5 times 3sqrt(2)`
`abs(vec(L))=60` unit