A baseball of mass m = 0.145 kg is suspended vertically from a tree by a string of length L = 1.1 m and negligible mass. Take z as the upward vertical direction. A short-duration force F = Fyj + Fzk is applied to the baseball by a bat, momentarily creating a torque τ about the top of the string.

Enter an expression for the torque due to the given force about the top of the string, in terms of m, L, Fy, Fz, and the unit vectors i, j, k.