Become a physicist and maybe one day you can tell me.
Answer:
The radius is
Explanation:
From the question we are told that
The speed at which the race car moves is 
The centripetal acceleration is 
Generally the centripetal acceleration is mathematically represented as

=> 
=>
The particle moves with constant speed in a circular path, so its acceleration vector always points toward the circle's center.
At time
, the acceleration vector has direction
such that

which indicates the particle is situated at a point on the lower left half of the circle, while at time
the acceleration has direction
such that

which indicates the particle lies on the upper left half of the circle.
Notice that
. That is, the measure of the major arc between the particle's positions at
and
is 270 degrees, which means that
is the time it takes for the particle to traverse 3/4 of the circular path, or 3/4 its period.
Recall that

where
is the radius of the circle and
is the period. We have

and the magnitude of the particle's acceleration toward the center of the circle is

So we find that the path has a radius
of

The potential energy of the model will be the greatest at point C while it will be the least at point E. Option B and D are correct.
<h3>
What is potential energy?</h3>
The potential energy of an object is due to its position. It can be given as the formula,

Where,
- potential energy
- mass
- gravitation acceleration
- height
From the formula since the mass and gravitation acceleration is constant, the potential energy of the model will depend upon the height only.
The potential energy will be greatest at point C because the relative position of the ball is the highest from the earth.
The potential energy will be lowest at point E because the height of the ball is the least in this position.
Therefore, the potential energy of the model will be the greatest at point C while it will be the least at point E.
Learn more about kinetic energy:
brainly.com/question/26320744