Answer: Frictional force
Step-by-step explanation:
Since the body is moving at constant velocity, this means that the acceleration of the body is zero. Frictional force is a force of opposition which tends to oppose the moving force of an object on a flat surface.
Mathematically, summation of force on the car along the road will be
Fm - Ff = ma
Fm = moving force
Ff = frictional force
m = mass of the body
a = acceleration of the body
Since a = 0, we have;
Fm -Ff = 0
Fm = Ff (which shows that the two forces acting on the body are equal and opposite)
This frictional force will tend to keep the body at equilibrium.