A 30 kg ball slides down a slope which is 60 m long and is at an angle of 20° above the horizontal. The slope is smooth, there is no

friction. The object starts with zero speed. At the bottom, it slides into a horizontal spring, which it compresses by 0.2 m before it stops. The spring is initially uncompressed . Calculate the initial mechanical energy of the balI. B. Calculate the constant of the spring.