Question

A rigid container equipped with a stirring device contains 2.8 kg of motor oil. Determine the rate of specific energy increase when heat is transferred to the oil at a rate of 1 W, and 1.5 W of power is applied to the stirring device. (Round the final answer to one decimal place.)

Answer 1

Rate of change of specific energy will be
`=(2.5)/(2.8)=0.8928j/kgsec`

Step-by-step explanation:

We have given mass of the motor oil m = 2.8 kg

Heat is transferred to the oil at a rate Q = 1 W

Power supply by stemming device
`W=-1.5Watt`

Applying first law to the device

`Q=W+dU`

`1=-1.5+dU`

`dU=2.5`

Rate of change of specific energy will be
`=(2.5)/(2.8)=0.8928j/kgsec`