A thin, uniform rod with negligible mass and length 0.200 m is attached to the floor by a frictionless hinge at point P. A horizontal spring with force constant k = 4.80 N/m connects the other end of the rod to a vertical wall. The rod is in a uniform magnetic field B = 0.340 T directed into the page. There is a current of I = 6.50 A in the rod.
Angle between rod and floor = 53.0 degrees
Direction of current is toward the floor
a. Compute the torque due to the magnetic force on the rod, for an axis at P.
(You can consider the total magnetic force on the rod to act at its center of mass.)
b. When the rod is in equilibrium and makes an angle of 53degrees with the floor, is the spring stretched or compressed?
c. How much energy is stored in the spring when the rod is in equilibrium?