Q. A 4.60 long, 480 steel beam extends horizontally from the point where it has been bolted to the framework of a new building under construction. A 67.0 construction worker stands at the far end of the beam. What is the magnitude of the torque where the beam is bolted into place?

Q. An infinite plane (take it as the x-y plane, and use cylindrical coordinates r,theta,z) has the potential distribution V(r,theta)=V0, rV(r,theta)=0, r>a

a) Use Green's function for a plane to find the potential phi(r,z) above the plane. (Don't evaluate the integral.)

b) Evaluate the integral for the case r=0, and find the potential on z axis.