Question

Precalculus- finding torque using cross products?

There is an example problem too, it didn't help me, but I'll it for reference:

Answer 1

Taking `+x`-axis towards east, `+y`-axis towards north and `+z`-axis out of the paper with location where ratchet is fixed on the nut as origin of coordinates.
Using similar figure as given in the example.

Applied force is `vecF =-42hatj\ N`
The radius vector for calculation of torque can be resolved in its components as `vecr=(-0.59cos38^@hati-0.59sin 38^@hatj)\ m`

Torque `vectau=vecrxxvecF`
Inserting above values we get

`vectau=(-0.59cos38^@hati-0.59sin 38^@hatj)xx(-42hatj)`
`=>vectau=(-0.59cos38^@hati)xx(-42hatj)`
`=>vectau=19.5hatk\ Nm`
`=>|vectau|=19.5\ Nm`