I would say that this is the first law of thermodynamics.
In physics, gravity is the natural force that causes things to fall toward the earth. The noun gravity can also mean seriousness or solemnity. Someone who conducts themselves with an air of gravity is someone who takes what they are doing seriously.
A) d. 10T
When a charged particle moves at right angle to a uniform magnetic field, it experiences a force whose magnitude os given by

where q is the charge of the particle, v is the velocity, B is the strength of the magnetic field.
This force acts as a centripetal force, keeping the particle in a circular motion - so we can write

which can be rewritten as

The velocity can be rewritten as the ratio between the lenght of the circumference and the period of revolution (T):

So, we get:

We see that this the period of revolution is directly proportional to the mass of the particle: therefore, if the second particle is 10 times as massive, then its period will be 10 times longer.
B) 
The frequency of revolution of a particle in uniform circular motion is

where
f is the frequency
T is the period
We see that the frequency is inversely proportional to the period. Therefore, if the period of the more massive particle is 10 times that of the smaller particle:
T' = 10 T
Then its frequency of revolution will be:

a) uniform velocity
b) zero or no acceleration
c) (see picture)
EXPLANATION:
(see picture)
Well, energy can be produced from the burning of fossil fuels which produce steam to spin turbines which generates electricity. But fossil fuels like coal and oil are no renewable.
Some renewable ways to get energy is water where they separate hydrogen from h2o because hydrogen can be made into energy. Also nuclear fission is another way to get energy. That's when in a nuclear power plant, the atoms nucleus is split which sends a large amount of energy.
Wind energy is another source of energy, which is from windmills. Another renewable energy source is solar energy. That's when u use solar cells, like some houses and calculators have, which generates a lot of energy, but only in the day since the sun doesn't shine in the nigh.
Hope I helped!!!