Well, first of all, the car is not moving at a uniform velocity, because,
on a curved path, its direction is constantly changing. Its speed may
be constant, but its velocity isn't.
The centripetal force on a mass 'm' that keeps it on a circle with radius 'r' is
F = (mass) · (speed)² / (radius).
For this particular car, the force is
(2,000 kg) · (25 m/s)² / (80 m)
= (2,000 kg) · (625 m²/s²) / (80 m)
= (2,000 · 625 / 80) (kg · m / s²)
= 15,625 newtons .
Answer:
1.40625 kg-m^2
Explanation:
Supposing we have to calculate rotational moment of inertia
Given:
Mass of the ball m= 2.50 kg
Length of the rod, L= 0.78 m
The system rotates in a horizontal circle about the other end of the rod
The constant angular velocity of the system, ω= 5010 rev/min
The rotational inertia of system is equal to rotational inertia of the the ball about other end of the rod because the rod is mass-less

=1.40625 kg-m^2
m= mass of the ball and L= length of the ball
The work done by the electric field is equal to the loss of electric potential energy of the proton in moving from its initial location to its final location:

where

is the proton charge,

and

are the voltages in the final and initial locations. Substituting, we get