Question

Compute the torque about the origin of the gravitational force F = −mg acting on a particle of mass m located at r = x + y. (Use the following as necessary: m, g, x, and y). Torque = F (cross) r

Please help

Answer 1

If F= - (m•g)•j and r = (x) •I + (y) •j.
τ= - (m•g•x) [i x j] – (m•g•y)[j xj] = (m•g•x)•k.
i, j, k are the unit vectors of Cartesian coordinate system.