Answer:
YOUR ANSWER IS GIVEN BELOW:
Explanation:
The abundance of helium in the universe and the redshift of light from the galaxies.
Answer:
A controlled variable does not change during a experiment
Explanation:
it's c
Length of the pipe = 0.39 m
Third harmonic frequency = 1400 Hz
For the third harmonic:
Wavelength = 
The center of the open pipe will host a node and the nearest anti - node from the center will be at the 0.25 × wavelength
Distance from center = 0.25 × wavelength
Distance = 
Plugging the value of the length of the pipe (L) = 0.39 m = 39 cm
Distance = 
Distance from the center to the nearest anti - node = 6.5 cm
Hence, the nearest distance to the anti - node from the center = 6.5 cm
So, option C is correct.
Answer:
Increases
Explanation:
The expression for the capacitance is as follows as;

Here, C is the capacitance,
is the permittivity of free space, A is the area and d is the distance between the parallel plate capacitor.
It can be concluded from the above expression, the capacitance is inversely proportional to the distance. According to the given problem, the capacitor is disconnected from the battery and the distance between the plates is increased. Then, the capacitance of the given capacitor will decrease in this case.
The expression for the energy stored in the parallel plate capacitor is as follows;

Here, E is the energy stored in the capacitor, C is the capacitance and Q is the charge.
Energy stored in the given capacitor is inversely proportional to the capacitor. The charge on the capacitor is constant. In the given problem, as the distance between the parallel plates is being separated, the energy stored in this capacitor increases.
Therefore, the option (c) is correct.
Answer:
Explanation:
Person A's velocity relative to the train is 0. Therefore, the pitch of the horn will not change.