And because of gravity it falls back down to the earth.
Answer: For ideal machine efficiency = 1. Hence M.A = V. R. The V. R of an ideal machine and the practical machine is a constant or is the same for both
The answer is True since thats what usually goes on
Answer:
Frequency, 
Explanation:
Wavelength of a light wave is 450 nm. It is required to find the frequency of this light wave. The speed of light is given by c. So,
f is the frequency of this light
So, the frequency of this light is 
.
<h2>
Answer:</h2>
The event horizon is the surface of a black hole, it is the border of space-time in which the events on one side of it can not affect an observer on the other side.
That is, at this border also called "point of no return", nothing can escape (not even light) and no event that occurs within it can be seen from outside.
