An m = 0.5 kg compresses a spring of force constant 500 N/m a distance 0.2 m from its natural length. When the block is released, it travels up a rough incline that is h = 0.4 m high and 2 m long. The block's final speed after ascending the incline is v = 4 m/s. (a) Calculate the amount of work done by the force of friction as the block slides up the rough incline, and then calculate the frictional force on the rough incline.