A 3.5 kg block is accelerated from rest by a compressed spring of spring constant 640 N/m. The block leaves the spring at the spring's relaxed length and then travels over a horizonatl floor with a coeffeicient of kinetic friction μ= .25. The fricitonal force stop the block in distance D= 7.8m. What are (a) the increase in the thermal energy of the block-floor system, (b) the maximum kinetic energy of the blovck, and (c) the original compression distance of the spring?