Is torque only produced when the force is applied perpendicular to the moment arm?

The primary benefit of taking into account a child's interests while selecting exercise activities is that the child will a. play more willing with others b. succeed at their favorite activity c. allow parents to relax afterwards d. gain motivation to exercise select the best answer from the choices provided.

Given the position vector of the particle r(t)=(t+1)i+(t^2−1)j+2t k, find the particle's velocity and acceleration vectors at t=1

What efficiency of a car's engine when heat input is 200,000 joules and waste heat is 150,000 joules? a. 75% b. 35% c. 25% d. 85%