# Question Video: Finding the Magnitude of the Moment of a Force about a Point Mathematics

If a force, having a magnitude of 498 N, is 8 cm away from point π΄, find the norm of the moment of the force about the point π΄, giving your answer in Nβm.

01:24

### Video Transcript

If a force, having a magnitude of 498 newtons, is eight centimeters away from point π΄, find the norm of the moment of the force about the point π΄, giving your answer in newton meters.

Weβll call our force magnitude, 498 newtons, capital πΉ. And the distance from point π΄ at which the force acts, eight centimeters, weβll call π. We want to solve for the norm of the moment of the force about point π΄. Weβll call that moment π.

In general, if we have a force vector π­ acting at a point separated from the point π΄ by a vector π, then the moment π΄ of that force π­ around point π΄ is equal to π cross π­.

In our case, because weβre solving for the norm of that moment, we can write a simplified version of the expression: π is equal to π times πΉ. Both π and πΉ are given in our problem statement. So weβre ready to plug in and solve for π.

When we do, we convert our distance into units of meters to be consistent with the required units of π. This product is equal to 39.84 newton meters. Thatβs the norm of the moment of the force about the point π΄.