Consider the situation of the pervious problem. (a) Calculate the force needed to keep the sliding wire moving with a constant velocity v. (b) If the force needed just after t = 0_ is `F_0`, find the time at which the force needed will be `F_0 /2/

In the last problem, calculate the force needed to pull out the inner coil at constant speed. The outer coil remains fixed.

A body of mass 10 kg is moving with a velocity of 100 m/s. find the force needed to stop it in 5 seconds.

A vehicle needs an engine of 7500 W to keep it moving with a constant velocity of 20 ms^(-1) on a horizontal surface. The force resisting the motion is

A vehicle needs an engine of 7500 W to keep it moving with a constant velocity of 20 ms^(-1) on a horizontal surface. The force resisting the motion is

A force F is needed to break a copper wire having radius R. the force needed to break a copper wire of radius 2R will be

Consider a situation similar to that of the previous problem except that the ends of the rod slide on a pair of thick metallic rails laid parallel to the wire. At one end the rails are connected by resistor of resistance R. (a) what force is needed ot keep the rod sliding at a constant speed v? (b) in this situation what is the current in the resistance R? (c) Find the rate of heat developed in the resistor. (d) find the power delivered by the external agent exerting the force on the rod.

Consider a situation similar ot that of the previous problem except that the ends of the rod slide on a pair of thick metallic rails laid parallel to the wire. At one end the rails are connected by resistor of resistance R. (a) what force is needed ot keep the rod sliding at a constant speed v? (b) in this situation what is the current in the resistance R? (c) Find the rate of heat developed in the resistor. (d) find the power delivered by the external agent exerting the force on the rod.

Consider a situation similar ot that of the previous problem except that the ends of the rod slide on a pair of thick metallic rails laid parallel to the wire. At one end the rails are connected by resistor of resistance R. (a) what force is needed ot keep the rod sliding at a constant speed v? (b) in this situation what is the current in the resistance R? (c) Find the rate of heat developed in the resistor. (d) find the power delivered by the external agent exerting the force on the rod.