Answer:

Explanation:
The equation for centripetal acceleration is
.
We know the wheel turns at 45 rpm, which means 0.75 revolutions per second (dividing by 60), so our frequency is f=0.75Hz, which is the inverse of the period T.
Our velocity is the relation between the distance traveled and the time taken, so is the relation between the circumference
and the period T, then we have:

Putting all together:

I think the answer is periodic motion.
Answer:
1- b: 2- a : 3- c : 4- d
Explanation:
it starts 2 move away from strting point, then no motion, then moves toward the start, the slows up.
If the same atoms appear on both sides, then it's balanced.
In this reaction, there are 4 Oxygens, 2 Carbons, and 2 Nitrogens on each side. So numerically, <em>it's balanced</em>. But I don't know enough chemistry to say whether the reaction is possible.
The sun always shines directly overhead at noon. This is because the equator always gets the equivalent amount of sunlight. The area always get 12 hours of sunlight, because it's 0 degrees north and south and it's at the center of the Earth.