motion of objects is caused by the force as stated by one of newtons law f=ma (m is mass, a is acceleration). if a constant force is applied on the object, the object moves at constant velocity (zero acceleration). if there is a net force applied, the object will change its velocity. in real life, a net force can be applied in an attempt to slow down or speed up an object. if you hit the break, a friction force from the metal plates will counteract with the angular velocity of the wheel, thus decreasing the velocity. if you hit a softball with racket, you ultimately applied a net force that will bounce back the ball with higher velocity. this examples demonstrate velocity and acceleration.
if the force applied at two ends extremes of the object, equal in magnitude, an equilibrium system is created. a see-saw with two identical masses at each extreme is in equilibrium because the torque forces produced cancel out each other.
a contact force is formed when two objects contact each other exerting different forces such as in friction force etc. a field force include magnetic force, electromagnetic force, electrostatic force. similarly, their magnitudes determine the motion of the object or particle. if you put the loop carrying a current between bar magnets, you the loop will spin at certain speed. if you use bigger bar magnets, the loop will spin faster.
hope that helps