Question

A body of mass 2kg is sliding with a constant velocity of 4m/s in a frictionless horizontal table. What is the force required to keep the body moving with the same velocity?

Answer 1

the force required is equal to the friction force

Answer 2

ANSWER:

F = 0. There is no force required to keep the body moving with the same velocity.

EXPLANATION:

As it is given in the question, the object is moving with a velocity of $4 m s^{-1}$, it is a constant velocity in which the object is moving. The acceleration is defined as the rate of change of velocity. And hence for the constant velocity, the acceleration is thereby said to be zero.

That the value of 'a' corresponding to zero. By the law of inertia when there is no external force applied to the object, the object will tend to remain in its original state that is if the object is in rest, it will remain in rest. If the object is in motion, it will be in motion.

$F=m \times a$

Where a = 0  

And hence F = 0.