An object maintains its motion under the continuous application of _________________ force. 

An object travels with a uniform velocity when the forces (pushing force and frictional force) acting on the object are balanced and there is no net external force on it. 

• If an unbalanced force is put on the object, there can be a change either in its speed or in the direction of its motion. 
• Thus, to accelerate the motion of an object, an unbalanced force is needed and the change in its speed (or) in the direction of motion will continue as long as the unbalanced force is applied. 
• In the absence of any force acting upon it, an object will retain the velocity it had attained prior to the force being removed and continue to move accordingly.