It’s red shift and blue shift because This only occurs when the frequency of the wave is made longer or shorter due to the movement of the source relative to the observer
The force of friction is zero.
Using F = m a = the force needed is 6 N which means no friction can be acting.
Answer:
d
Explanation:
First law of thermodynamics
It is also known as energy conservation law.It state that net work in a cyclic process is equal to net heat in that cycle.
From first law
Q=ΔU + W
ΔU = Q - W
ΔU is the change in internal energy of gas.
Q is heat transfer from the system or to the system.
W is the work done by the system or on the system.
If work done on the system then it will be taken as positive and If work done by the system then it will be taken as negative.
If heat taken by system it will taken as positive and If heat rejected by system it will taken as negative.
So Q will be positive if system gains heat and work will be positive if work is done on the system.
I believe this would be frequency, as wavelength measures the waves themselves, and a period is a section of time. Wave speed is the speed of their movement.
