A 0.40 kg block can slide up and down a rough 10-m-high, 30-m-long slope. At the bottom, a stiff spring with spring constant 800 N/m is compressed 0.50 m and used to launch the block up the slope. The friction force on the block from the slope is 1.2 N. Use g = 10 m/s2. Match the answers with questions. - the change in spring potential energy (Usp) - the change in gravitational potential energy (Ug) - the change in thermal energy (Eth) - the change in kinetic energy (K) A. 36 B. -36 J C. 18 J D. -18 J E. -40 J F. 100 J G. 24 J H. -100 J I. 40 J J. -24 J