Suppose the force of friction on a sliding object is 25 N. What is the force needed to maintain a constant velocity?

25

25 N

To determine the force needed to maintain a constant velocity for a sliding object, we need to consider Newton's first law of motion, which states that an object will remain at rest or move in a straight line at a constant velocity unless acted upon by an unbalanced force.

In this case, the force needed to maintain a constant velocity is equal in magnitude but opposite in direction to the force of friction. This is known as the force of tension (T), which acts in the direction opposite to the force of friction.

Therefore, the force needed to maintain a constant velocity is 25 N in the direction opposite to the force of friction.

Please note that this assumes there are no other forces acting on the object. If other forces are present, such as gravitational force or applied forces, they need to be taken into account to determine the net force and the force required to maintain a constant velocity.