identify-the-sign-of-u-for-each-indicated-system-a-a-gas-sample-is-compressed-ad

Question

Identify the sign of ΔU for each indicated system.
a) A gas sample is compressed adiabatically. (System = gas)
b) Hot coffee is cooled in a refrigerator. (System = coffee)
c) A worker pushes a trolley along a ramp (System = worker)

Accepted Answer

a) ΔU_{sys} \u003e 0; b) ΔU_{sys} \u003c 0; c) ΔU_{sys} \u003c 0

Answer

a) ΔU_{sys}  0; c) ΔU_{sys} \u003e 0

Answer

a) ΔU_{sys} \u003c 0; b) ΔU_{sys} \u003c 0; c) ΔU_{sys} \u003c 0

Answer

a) ΔU_{sys} \u003e 0; b) ΔU_{sys} \u003e 0; c) ΔU_{sys} \u003c 0