Question

An insect of mass m = 1 gm moves with a velocity v = (i - 2j+k)m/s. Find its angular momentum L about the origin O
when the insect passes through the point (-1,1,2)m. Use L=r×mv​

Answer 1

Answer:

L (vec) = 5i(cap)+3j(cap)-k(cap)

Explanation:

let rdius be r,

r(vec) = $(-1-0)^{2} i(cap)+(1-0)^2j(cap)+(2-0)^2k(cap)$

r(vec) = -i(cap)+j(cap)+2k(cap)

v(vec) = i(cap)-2j(cap)+k(cap)

L(vec) = r (vec) * 1 * v(vec)

L(vec) = $\left[\begin{array}{ccc}i&j&k\\-1&1&2\\1&-2&1\end{array}\right]$

Hence L (vec) = 5i(cap)+3j(cap)-k(cap)