Question

If the total energy change of an system during a process is 15.5 kJ, its change in kinetic energy is -3.5 kJ, and its potential energy is unchanged, calculate its change in specificinternal energy if its mass is 5.4 kg. Report your answer in kJ/kg to one decimal place.

Answer 1

Answer:

The change in specific internal energy is 3.5 kj.

Explanation:

Step1

Given:

Total change in energy is 15.5 kj.

Change in kinetic energy is –3.5 kj.

Change in potential energy is 0 kj.

Mass is 5.4 kg.

Step2

Calculation:

Change in internal energy is calculated as follows:

$\bigtriangleup E=\bigtriangleup KE+\bigtriangleup PE+\bigtriangleup U$$15.5=-3.5+0+\bigtriangleup U$

$\bigtriangleup U=19$ kj.

Step3

Specific internal energy is calculated as follows:

$\bigtriangleup u=\frac{\bigtriangleup U}{m}$

$\bigtriangleup u=\frac{19}{5.4}$

$\bigtriangleup u=3.5$ kj/kg.

Thus, the change in specific internal energy is 3.5 kj/kg.