Answer:
- The diameter of the molecule of oil is

Explanation:
We define density as

So, the volume for our oil will be




the volume for a cylinder with radius r and height h is

So, we can obtain the height of the droplet of oil as:

the radius is


And this is the diameter of the oil molecule.
Player A needs the least amount of energy. The ball is light weight and she is closest to the goal so the momentum need to kick the ball will be the least and the distance is has to travel is the shortest. But player C needs the most amount of energy. The ball is heavy so it will take the most momentum to move the ball and over such a long distance. Hope this help idrk.
To develop this problem it is necessary to apply the concepts related to Gravitational Potential Energy.
Gravitational potential energy can be defined as

As M=m, then

Where,
m = Mass
G =Gravitational Universal Constant
R = Distance /Radius
PART A) As half its initial value is u'=2u, then



Therefore replacing we have that,

Re-arrange to find v,



Therefore the velocity when the separation has decreased to one-half its initial value is 816m/s
PART B) With a final separation distance of 2r, we have that

Therefore




Therefore the velocity when they are about to collide is 
<h2>
The child swing through the swing's equilibrium position 6 times during the course of 3 periods.</h2>
Explanation:
One period means time taken to complete one revolution.
In case of swings in one period time it travels the same position through two times.
Here we need to find how many times does the child swing through the swing's equilibrium position during the course of 3 period(s) of motion.
For 1 period = 2 times
For 3 periods = 3 x For 1 period
For 3 periods = 3 x 2 times
For 3 periods = 6 times
The child swing through the swing's equilibrium position 6 times during the course of 3 periods.
It takes sunlight 8 minutes to reach earth , so yes