Answer:
The system loses 90 kJ of heat
Explanation:
We can answer the question by using the 1st law of thermodynamics, which states that:

where
is the change in internal energy of the system
is the heat absorbed by the system (positive if absorbed, negative if released by the system)
is the work done by the system (positive if done by the system, negative if done by the surrounding on the system)
In this problem, we have:
is the work done (negative, because it is done by the surrounding on the system)
is the increase in internal energy
Using the equation above, we can find Q, the heat absorbed/released by the system:

And the negative sign means that the system has lost this heat.
The answer to your question is "A. a lower frequency of the siren.
Because the person in back of the ambulance will hear a lower frequency of the siren. This is because the waves are stretched out. A longer wavelength results in a lower frequency.
Answer:A brick is released with no initial speed from the roof of a building and strikes the ground in 2.50 s, encountering no ..