An 11.5 kilogram block rests on a horizontal table and is attached to one end of a mass less, horizontal spring. By pulling horizontally on the other end of the spring, someone causes the block to accelerate uniformly and reach a speed of 3.36 meter per second in 0.728 second. In the process, the spring is stretched by 0.194 meter. The block is then pulled at a constant speed of 3.36 meter per second, during which time the spring is stretched by only 0.0541 meter.
(a) Obtain the spring constant of the spring?
(b) Obtain coefficient of kinetic friction between block the table.