a. By the work-energy theorem, the total work required to stop the car is equal to the change in its kinetic energy,
<em>W</em> = 0 - 1/2 (750 kg) (25 m/s)² ≈ -230 kJ
b. The car covers a distance <em>x</em> as it stops such that
<em>W</em> = (-725 N) <em>x</em> ==> <em>x</em> ≈ 320 m
The size of the force varies inversely as the square of the distance between the two charges. Therefore, if the distance between the two charges is doubled, the attraction or repulsion becomes weaker, decreasing to one-fourth of the original value
Answer:

Explanation:
The speed is by definition the distance traveled divided over the time it takes to travel that distance. In this case, this distance is the circumference of the wheel, so we have:

where we have written the circumference in terms of its radius.
For our values we then obtain the value:
