Question1
A current of 1A is injected into the earth at the bottom of a borehole. Derive an expression for the Voltage at distance R from the injection point. Assume that the earth has a uniform linear conductivity and that the borehole diameter is negligible (Use J = σE).
Question2
A bicycle wheel is rotating with an angular velocity of 3.1 rev/s. The brakes coefficient of kinetic friction between the wheel and the brakes is 0.87, find out the number of revolutions the wheel makes in coming to rest. The moment of inertia of the wheel is 0.24 kg*m and its radius is 0.32 m.
Question3
Consider a crate at rest on a factory ?oor. As a pair of workmen start lifting it, does the support force on the crate provided by the ?oor increase, decrease, or remain unchanged? What happens to support force on the workmen's feet?