Newton's First Law of Motion
An object at rest will remain at rest unless acted on by an unbalanced force. An object in motion continues in motion with the same speed and in the same direction unless acted upon by an unbalanced force. This law is often called "the law of inertia".
This means that there is a natural tendency of objects to keep on doing what they're doing. All objects resist changes in their state of motion. In the absence of an unbalanced force, an object in motion will maintain this state of motion.
Thus, in an ideal world, on a frictionless surface, an object can keep moving in the same direction with the same speed for eternity.
This means that there is a natural tendency of objects to keep on doing what they're doing. All objects resist changes in their state of motion. In the absence of an unbalanced force, an object in motion will maintain this state of motion.
Thus, in an ideal world, on a frictionless surface, an object can keep moving in the same direction with the same speed for eternity.
According to Newton's First Law of Motion, the skateboard should remain in motion if there were no additional force acting upon the skateboard. However, because there is a rock impeding the motion of the skateboard, the skateboard is slowed to a stop. The graduated cylinder on the skateboard, on the hand, continues to move in the same direction with the same speed because the force did not directly act upon the cylinder. As a result, the cylinder falls and breaks. A similar example illustrates why seat-belts are important when riding a car.
Newton's Second Law of Motion
The relationship between an object's mass m, its acceleration a, and the applied force F is F = ma. Acceleration and force are vectors; in this law the direction of the force vector is the same as the direction of the acceleration vector.
This means that more mass requires more force to accelerate; more mass requires more force to travel the same distance.
This means that more mass requires more force to accelerate; more mass requires more force to travel the same distance.
Force=Mass x Acceleration
F=ma
= mv/t
Ft=mv
F=ma
= mv/t
Ft=mv
Notice that Newton's Second Law also explains the Law of Momentum and Impulse!
Please also note that force refers to net force in this equation. If two forces happen to balance out, then there will be zero net force and thus zero acceleration. When in doubt, draw a FREE BODY DIAGRAM!
Please also note that force refers to net force in this equation. If two forces happen to balance out, then there will be zero net force and thus zero acceleration. When in doubt, draw a FREE BODY DIAGRAM!
Newton's Third Law of Motion
For every action there is an equal and opposite re-action.
So whenever Object A exerts a force on Object B, Object B will exert a force with the same magnitude but in different directions back onto Object A. This is the principle of normal force.
Some may ask, then why does an object move at all if the action and reaction forces balance out?
It is because the two forces are acted upon two different objects.
So whenever Object A exerts a force on Object B, Object B will exert a force with the same magnitude but in different directions back onto Object A. This is the principle of normal force.
Some may ask, then why does an object move at all if the action and reaction forces balance out?
It is because the two forces are acted upon two different objects.
Newton's Third Law can explain how a rocket works. The rocket pushes down on the ground with the powerful engines as the action force, the reaction force is from the ground acting upon the rocket and pushing it up.