In a gear train with two gears, the gear ratio is defined as follows
where

is the angular velocity of the input gear while

is the angular velocity of the output gear.
This can be rewritten as a function of the number of teeth of the gears. In fact, the angular velocity of a gear is inversely proportional to the radius r of the gear:

But the radius is proportional to the number of teeth N of the gear. Therefore we can rewrite the gear ratio also as
Well first of all, a planet doesn't have a semimajor axis, although it's orbit does.
In an orbit with a smaller semimajor axis, the planet moves faster, and its orbital period is shorter.
That's why the International Space Station circles the Earth in less time than the Moon does.
The sum is the result of adding 9260 and 3240 together. Each number can
be broken down into constituent parts in order to make addition easier.
Each place in the number represents its value, so a 2 in the hundreds
place represents 200.
You can separate numbers out this way to
make it easier to add them. 9260 can be broken down into 9000+200+60
while 3240 is 3000+200+40. You can then add these six numbers together.
60+40 = 100
200+200 = 400
9000+3000 = 12000
Then add your three partial results together to receive the final answer:
12000+400+100 = 12500
It is as a result of gravity. (D)
This is as stated by Newton's law of universal gravitation. That two objects in the universe attract one another with a force that is proportional to the product of their masses and inversely proportional to the square of the distance apart.
The constant of proportionality is the Universal Gravitational Constant.
G = 6.673 × 10⁻¹¹ Nm²kg⁻²