Consider the situation of the previous question from a frame moving with a speed `v_0` parallel to the initial velocity of the block? b. What is the work done by the kinetic friction?

A ball is given a speed v on a rough horizontal surface. The ball travels through a distance l on the surface and stops. A. What are the initial and final kinetic energies of the ball? b. What is the work done by the kinetic friction?

A 100 kg block is started with a speed of 2.0 m s^(-1) on a long, rough belt kept fixed in a horizontal position. The coefficient of kinetic friction between the block and the belt is 0.20. (a) calculate the change in the internal energy of the block-belt system as the block comes to a stop on the belt. (b) consider the situation from a frame of reference moving at 2.0 m s^(-1) along the initial velocity of the block. as seen from this frame, the block is gently put on a moving belt and in due time the block starts moving with the belt at 2.0 m s^(-1) , calculate the increase in the kinetic energy of the block as it stops slipping past the belt. (c ) find the work done in this frame by the external force holding the belt.

Consider the situation of the previous problem. Consider the fastest electron emitted parallel to the large metal plate. Find the displacement of this electron parallel to its initial velocity before it strikes the large metal plate.

Consider the situation of the previous 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.

A small block of mass m is kept on a rough inclined surface of inclination theta fixed in an elevator. The elevator goes up with a uniform velocity v and the block does not slide on the wedge. The work done by the force of friction on the block in time t will be

Consider the situation of the previous problem. A charge of 2.0xx 10 ^(-4) C is moved from the point A to the point B. find the change in electrical potential energy U_B-U_A for the cases (a) , (b) and ( c ).

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.

A uniform rod of mass M and length a lies on a smooth horizontal plane. A particle of mass m moving at a speed v perpendicular to the length of the rod strikes it at a distance a/4 from the centre and stops after the collision. Find a. the velocity of the cente of the rod and b. the angular velocity of the rod abut its centre just after the collision.

Consider an object of mass 2 kg moved by an external force 20 N in a surface having coefficient of kinetic friction 0.9 to a distance 10 m. What is the work done by the exteranl force and kinetic friction? Comment on the result. (Assume g = 10 m^(-2) )