Question

() A force P=3i+2 - 4 k is applied at the point (1,-1,2). Find the moment of the force about
the point (2,-1,3).​

Answer 1

Answer:

Let moment of force be M.

M = r × F

⇒ M = (i + 0j + k) × (3i + 2j - 3k)

⇒ M = 3i (i + 0j +k ) + 2i(i + 0j + k) - 3k(i + 0k +k)

⇒ M = 3j + 2k + 2j + (-3j)

⇒ M = 2k + 2j