Answer:

Explanation:
Using Kepler's third law, we can relate the orbital periods of the planets and their average distances from the Sun, as follows:

Where
and
are the orbital periods of Mercury and Earth respectively. We have
and
. Replacing this and solving for

The andromeda galaxy is approaching our galaxy with a radial velocity of 120 km/s. given the galaxies present separation of 800 kpc, and neglecting both the transverse component of the velocity and the effect of gravity in accelerating the motion, estimate when the two galaxies will collide.
The Andromeda Galaxy, also known as Messier 31, M31, or NGC 224 and originally the Andromeda Nebula, is a barred spiral galaxy that is 2.5 million light-years away from Earth and the closest big galaxy to the Milky Way. It has a diameter of roughly 46.56 kiloparsecs.
The Milky Way, which houses the Solar System and Earth, and the Andromeda Galaxy are anticipated to collide in roughly 4.5 billion years. This galactic collision will take place between the two largest galaxies in the Local Group. The Andromeda galaxy is the brightest galaxy outside of our solar system. It is the furthest object that the majority of us humans can see with our unaided eyes at a distance of 2.5 million light-years.
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The answer is B. Both NPN and PNP transistors consist of a base composed of an N-type material.