Question

a force of [4i-3j+5k] is applied at a point whose position vector is [7i+4j-2k] find the torque of force about the origin​

Answer 1

Torque = F×r

= [4i - 3j + 5k] × [7i + 4j - 2k]

= [(-3)(-2)-(4)(5)]i+[(4)(-2)-(7)(5)]j+[(4)(4)-(7)(-3)]k

= -14i - 43j + 37k

Magnitude: √[(-14)^2+(-43)^2+(37)^2

= √3414

= 58.43 J