Newton’s 2nd Law Newton's second law of motion pertains to the behavior of objects for which all existing forces are not balanced.

Newton’s Second Law The second law states that the acceleration of an object is dependent upon two variables - the net force acting upon the object and the mass of the object. The acceleration of an object depends directly upon the net force acting upon the object, and inversely upon the mass of the object.

As the force acting upon an object is increased, the acceleration of the object is increased. As the mass of an object is increased, the acceleration of the object is decreased.

Consider a man pushing a pick up truck.

Increased Force As the force acting upon an object is increased, the acceleration of the object is increased.

Increased Mass As the mass of an object is increased, the acceleration of the object is decreased.

Newton's second law of motion can be formally stated as follows: The acceleration of an object as produced by a net force is directly proportional to the magnitude of the net force, in the same direction as the net force, and inversely proportional to the mass of the object.

The Second Law is concerned with relating acceleration to mass and net force. Newton's second law of motion explains how an object will change velocity if it is pushed or pulled upon. Firstly, this law states that if you do place a force on an object, it will accelerate (change its velocity), and it will change its velocity in the direction of the force. So, a force aimed in a positive direction will create a positive change in velocity (a positive acceleration). And a force aimed in a negative direction will create a negative change in velocity (a negative acceleration).

Newton's first law in everyday terms: Newton's First Law (Law of Inertia) Newton's first law in everyday terms: ­An object at rest will stay at rest, forever, as long as nothing pushes or pulls on it. An object in motion will stay in motion, traveling in a straight line, forever, until something pushes or pulls on it.

The "forever" part is difficult to swallow sometimes. However, it is easy to imagine that an object at rest will remain at rest forever, until pushed or pulled by something. Now, just take that same idea and apply it to an object in motion.

­But imagine that you have three ramps set up as shown below ­But imagine that you have three ramps set up as shown below. Also imagine that the ramps are infinitely long and infinitely smooth. You let a marble roll down the first ramp, which is set at a slight incline. The marble speeds up on its way down the ramp. Now, you give a gentle push to the marble going uphill on the second ramp. It slows down as it goes up. Finally, you push a marble on a surface that is perfectly horizontal. In this case, the marble will neither slow down nor speed up. In fact, it should keep rolling. Forever. According to Newton's first law, the marble on that bottom ramp should just keep going. And going.

Physicists use the term inertia to describe this tendency of an object to resist a change in its motion. The Latin root for inertia is the same root for "inert," which means lacking the ability to move. So you can see how scientists came up with the word. What's more amazing is that they came up with the concept. Inertia isn't an immediately apparent physical property, such as length or volume. It is, however, related to an object's mass. To understand how, consider the sumo wrestler and the boy shown below. Which person in this ring will be harder to move? The sumo wrestler or the little boy?

Let's say the wrestler on the left has a mass of 136 kilograms, and the boy on the right has a mass of 30 kilograms (scientists measure mass in kilograms). Remember the object of sumo wrestling is to move your opponent from his position. Which person in our example would be easier to move? Common sense tells you that the boy would be easier to move, or less resistant to inertia.

You experience inertia in a moving car all the time You experience inertia in a moving car all the time. In fact, seatbelts exist in cars specifically to counteract the effects of inertia. Imagine for a moment that a car at a test track is traveling at a speed of 55 mph. Now imagine that a crash test dummy is inside that car, riding in the front seat. If the car slams into a wall, the dummy flies forward into the dashboard. Why? Because, according to Newton's first law, an object in motion will remain in motion until an outside force acts on it. When the car hits the wall, the dummy keeps moving in a straight line and at a constant speed until the dashboard applies a force. Seatbelts hold dummies (and passengers) down, protecting them from their own inertia.

Newton’s Laws 1st Law Inertia 2nd Law F=ma 3rd Law Action/Reaction