Momentum

Momentum

Momentum, as described in the Webster's dictionary, is the strength or force that something has when it is moving. We use the letter P to describe because m is used by mass and getting those two things confused is so not the haps.  

Formulas Used in Momentum:

Momentum (P) = m (mass) x v (velocity)

Impulse (change of P) = F (average Force) x t (change in time)

One of the key things you need to understand about momentum is the Law of Conservation of Momentum (in isolated system, momentum will we be conserved). For example, an apparatus (see picture below) is a prime example of an isolated system where momentum is conserved. Through collision when you hit one ball from one side of the apparatus, the ball on the opposing side of the apparatus is the one that moves. But you also have to notice that none of the other balls in the middle move when the initial ball is moved, only the ball on the opposing end. This demonstrates that the momentum is distributed through all the balls and it's actually pretty cool to watch. 

Momentum: Now what about situations where momentum is not in a conserved, isolated area such as the apparatus? Would the objects go all over the place in a chaotic fashion? Depending on their mass and velocity, maybe. 

In the picture above we can see a great example of momentum and how it is distributed among these pool balls. By apply enough force onto the Que. ball, and by hitting the pyramid of balls, breaking the balls is not a hard thing to do. But notice how the balls distribute, the point of breaking the balls in the first place is to distribute them across the table. This is achieved through momentum. Now how exactly does this happen? Well as described in the definition above, momentum is the strength or force that something has when it is moving or accelerating and when that strength or force is applied with the Que. ball it causes the balls to move. Here ends the reading. 

Forces that Accelerate

Forces That Accelerate

Did you know that according to Newton's Third Law; for every action, there is an equal and opposite reaction and for every force there is an equal and opposite force? Therefore, every time you hit something that thing is hitting you with an equal and opposite force BUT notice that when you hit things that have a significantly smaller mass than you do, that thing is obliterated, so how exactly are the forces the same if the object you hit was no more after you hit it? The answer is simple, the reason the object you hit was obliterated is because it was hit the the same force that you hit it, unfortunately the mass of the object you hit was a lot smaller than your mass AKA māke i ka mea!!!!!!

The picture above is a perfect example of forces that accelerate, although you cant really tell, the cup on the table IS ACCELERATING! It is accelerating down into the table thus putting force on the table, BUT according to Newton's Third Law, the table is supporting the cup with an equal and opposite force pushing on the cup now making it a BALANCED FORCE. We call this balanced force, the Normal force and this theory applies to any objects on a surface. 

 

Newton's First Law Inertia

Newton's first law is inertia. Now, what is inertia? Well, according to Newton's First Law, an object at rest tends to stay at rest unless acted upon by an outside, unbalanced force. For example, if there is an object resting on a table top and there is a sheet of paper pulled out from under it, the object will stay in the position it is in unless unbalanced forced is applied to it. The picture above is a prime example of this, the checker sitting on top of the wooden hoop fell straight into the jar. Now why is that? Well, because there was no force being exerted onto the checker piece, it fell into the jar when the hoop was moved. If you had used the hoop to make the checker unbalanced then it probably wouldn't go into the jar.

Projectile Motion

            In the video below, we can see an example of projectile motion; the motion of the tennis ball when it leaves the hands of Joie (left) and the distance it traveled it hit the ground. The shape of the ball as it falls toward the ground is called parabolic motion. Now although you cant really see how high Joie is off the ground, she is standing on a tall chair that makes her about 6 feet off the ground and she threw the ball with an initial speed of 0.2 meters per second. How would we use math to determine where on the ground the ball landed?

Well, by using physics we can determine where the ball landed without actually measuring how far away from Joie it landed. But before we know far away it landed we have to figure out how long it was in the air. By using the d=1/2at^2 formula we can determine the time, then we would go on to use the d=vt formula to find the distance and it is as simple as that!