If a force of 10 n along+x direction is acting on a object. what other force can be used to balance this force?

A frictional force of 10N on the opposite direction can be used to balance the given force.

Explanation:

The net force is the sum of all forces acting on the object in different directions (x,y):

 (1)    

Where represents the net force, m is the mass and a is the acceleration.

 (2)

is the sum of the forces that are in the x direction, for this particular case has to be equal to zero to be balanced.

So a force with the same magnitude but opposite direction is needed (-x).

Hence, a frictional force of 10N in the opposite direction can be used to balance the given force.

truck y has a greater velocity than truck x.