Momentum

Momentum is a very confusing topic for me, especially when you talk about change in momentum (impulse) versus change in speed. It is hard for me to tell the difference. In this picture a football player is getting tackled into the ground. The whole way down after he is hit there is no impulse but once he begins to hit the ground the impulse has a big small force and a large contact time, that is the same as if he his a hard surface because there would be a great force over a small contact time, they balance out. Overall he has a large momentum because has has a large mass and a large velocity moving forward.

Forces that Accelerate

I was sitting at Sandy Beach also known as “Sandys” and I realized that the blow hole was really blowing hard. So I grabbed my camera and took a sequence of pictures with it. I got pictures of when it began to blow, when it was in mid air still moving up and when all of the water was floating. This is related to physics because when the water first shot out of the hole, it was accelerating which meant that the velocity was increasing because of the pressure in the hole. As soon as all of the water left the hole it continued to move upward but it wasn’t accelerating because there was no force acting upon it. After a few seconds in mid air it began to fall because gravity downward was greater than the acceleration upward.

Newtonʻs Law #1

All of Newton’s laws make sense and the one that I will be talking about is Newton’s first law. His first law is “objects in motion/ at rest tend to stay in motion/ at rest unless acted upon by an outside, unbalanced force”. So I chose a skate board because it is obviously true for this law. When the skateboard is sitting at rest on flat ground it will continue to stay in the same spot unless a person or something else touches it. When a skateboard is moving it will continue to move until the force of friction, gravity and resistance is too great for the board to continue to move. Also it will stop moving if a person or another object hits it or touches it. 

Projectile Motion #3

This picture was taken at the state championship meet for cross country, the meet took place at island school on the island of Kauai. All of the people in this picture are projectiles because they are moving through the air. When they go in the air they move like a parabola. Everyone moves like a parabola in the air because gravity is always constant and gravity is always on. If there was no gravity then we wouldnʻt be able to run. Also if there was no gravity then objects in the air wouldnʻt move like a parabola, there would be no constant motion map for projectiles. It would be very hard to do physics with out any gravity on earth. We would have to find a new constant for something similar to gravity.