An object is moving across a surface, but it does not gain or lose speed. which best describes the object’s force?

the net force is positive.
the net force is zero.
the positive force is greater than the negative force.
the negative force is greater than the positive force.

option (b)

Explanation:

According to the Newton's second law, the force acting on a body is the product of mass of the body and the acceleration of the body.

Force = mass x acceleration

As net force is zero, so acceleration is zero because mass cannot be zero.

As acceleration is zero, it means the velocity is constant.

Net force is zero.

that would be because of both gravity and friction. so     c

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.