Q1. A coiled telephone cord forms a spiral with 56 turns, a diameter of 1.30 cm, and an unstretched length of 60.0 cm. Determine the self-inductance of one conductor in the unstretched cord.
Q2. At a construction site, a 67.0 kg bucket of concrete hangs from a light (but strong) cable that passes over a light friction-free pulley and is connected to an 85.0 kg box on a horizontal roof. The cable pulls horizontally on the box, and a 50.0 kg bag of gravel rests on top of the box. The coefficients of friction between the box and roof are shown (µs=0.700, µk=0.400). The system is not moving. Find out the friction force on the bag of gravel. Find the Friction force on the box.