A heat pump is a device used to heat something, in this case water. Heat pump takes heat from colder object and transfers it to warmer object. This is opposite to <span>direction of spontaneous heat transfer which from warmer to colder object.
In this problem a room got colder while water got warmer. This is due to work done by heat pump. This is what is described in correct answer c).
a) is not correct because it shows </span>direction of spontaneous heat transfer. It also says that <span>Aleksei’s family purchased a new water heater and in description givne in a) it would mean that water got colder.
b) is not correct because if the </span><span>burning fuel increased the thermal energy in the air it would mean that this room got warmer than rest of house.
d) is not correct because burning fuel does not absorb </span><span>thermal energy. It releases it.</span>
Answer:
The Value is 
Explanation:
The explanation is shown on the first uploaded image
Answer:
Currently in the united states using parallel system
Explanation:
because you can walk with the twomodes with internal combustion engine or running on electric power.
Answer:
C is halved
Explanation:
The frequency and the wavelength of a wave are related by the equation:
where
v is the speed of the wave
f is the frequency
is the wavelength
From the equation above, we see that for a given wave, if the wave is travelling in the same medium (and so, its speed is not changing), then the frequency and the wavelength are inversely proportional to each other.
Therefore, if the frequency doubles, the wavelength will halve in order to keep the speed constant:
