(a) In air at 0°C, a 1.60-kg copper block at 0°C is set sliding at 2.50 m/s over a sheet of ice at 0°C. Friction brings the block to rest. Find the mass of the ice that melts. To describe the process of slowing down, identify the energy input Q , the work input W, the change in internal energy ΔEint, and the change in mechanical energy ΔK for the block and also for the ice.
(b) A 1.60-kg block of ice at 0°C is set sliding at 2.50 m/s over a sheet of copper at 0°C.
Friction brings the block to rest. Find the mass of the ice that melts. Identify Q, W, ΔEint, and ΔK for the block and for the metal sheet during the process.
(c) A thin 1.60-kg slab of copper at 20°C is set sliding at 2.50 m/s over an identical stationary slab at the same temperature. Friction quickly stops the motion. If no energy is lost to the environment by heat, find the change in temperature of both objects. Identify Q, W, ΔEint, and ΔK for each object during the process.
Solution:
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