Answer:
<h2><u>Rheostat:</u></h2>
=> Rheostat is an electric device used as a variable resistance, like the regulator of the fan. It is used to change the electric resistance in the electric circuit.
<h2><u>Principle / Rule:</u></h2>
=> Rheostat works on the principle of Ohm’s law. Ohm’s law states that current in a circuit is inversely proportional to the resistance at the given temperature.

The answer is Newton's 3rd Law. The reason why is because a force is a push or a pull that acts upon an object as a results of its interaction with another object. ... These two forces are called action and reaction forces and are the subject ofNewton's third law of motion. Formally stated, Newton's third law is: For every action, there is an equal and opposite reaction.
P=mv
pi =pf
(68x2.79)+(131x0) = 199v
v= 0.95 m/s
Its the amount of matter in something.
for example, a large truck as compared to a mouse, the truck would have much greater of a mass.
<span>The heavier the body is, the stronger
its gravitational pull. Just like earth, we feel gravitational pull because we
are attracted to earth and so is the moon. Also, the sun is heavier than the
earth and therefore, we are attracted to the sun because of its gravitational
pull. When the earth revolves around the sun, both of them releases
gravitational waves. Gravitational waves are ripples of waves travelling
outward from the source. The more massive the orbit of two bodies, the more it
emits gravitational wave. And everything around it that is near within the wave
experiences a ‘pull’ toward the orbiting bodies. The advantages we get when we
can measure gravitational waves are; one, we can measure the activity between
two bodies in orbit in the universe, two, scientist can estimate the merging of
two bodies in the universe every 15 minutes by using LIGO and three, we can
know the behavior of other bodies that we did not know exist.</span>