Practice question

**Work and heat** both energy transfer modes, work organized, e.g., lifting weight, compressing gas, electrical current, heat random due to temperature difference, work can be completely converted to heat via friction, but heat cannot be completely converted to work (second law), energy transfer modes include work (mechanical, electrical) and heat (conduction, convection, radiation). In an adiabatic process ( Δ Q = 0 ), the change in internal energy ( Δ U ) is entirely due to work done ( Δ U = -Δ W ). Work done by or on the system adjusts the internal energy, as no heat is exchanged. Using first law ΔU