Today i went to my grandma's house for dinner and tossed a tennis ball around with my cousin Caiden. When he threw me the ball i saw that it was spinning and realized that it has rotational motion. Rotational motion means that the axis is within the object. There is a distinct difference between rotational and circular motions. Rotational motion is like spinning around in place, and circular motion is like walking around a track. Rotational motion has torque. Torque is defined as a force that causes or opposes rotation. The equation for torque is τ = rF when the force is perpendicular to the lever arm. The lever arm is the distance between the force and the hinge/axis. τ is torque, r is the lever arm distance and F is the force. With the tennis ball, the lever arm distance is the radius of the ball, the axis is the the center of the ball, and the force is Caiden's fingers when he tosses the ball in the air.

This past Friday i had a soccer game for jv soccer against punahou. We tied 0-0 :[ but i realized theres a lot of physics in soccer. Whenever the ball is kicked momentum is transferred from the players foot, leg, or head to the ball. Kicking the ball exerts more force on the players foot than simply stopping the ball because the ball has a greater change in velocity (final velocity - initial velocity). If the ball is coming at me with a speed of -5 m/s and i kick it to make it go 20 m/s (strong yah?) the change in velocity was 25. I had to not only stop the ball, but also kick it forward (in the opposite direction). This picture shows my back because as i was looking for a picture i realized that i make funny faces when i play. That punahou girl is making a funny face pretty similar to how my face looks in all the pictures. Except mine is weirder. So this picture is my favorite. for sure.

This friday was homecoming (duh) and as I watched the game from the sidelines with 2 super cool waterbottles in my hands i saw Kellen get his first tackle! When he came off the field and I went to give him water (since im such a dedicated watergirl) he told me how it felt like he absorbed the force of the guy he was tackling. Being the cool kid that I am i thought omg thats physics! Both Kellen and the WOLA player had kinetic energy, or the energy of objects in motion. The force (Kellen) was going in the opposite direction of the object (the WOLA player) so Kellen did negative work. His negative work stops the guy and lowers his kinetic energy to zero. The negative work decreases the energy. The picture right therrre has nothing to do with the homecoming but its the best i could do since i couldnt find any (I dont think Mr. Linsky posted the pictures yet). But it has to do with football so close enough I guess.

So basically this icon thing describes me && physics. It's pretty fun like when we stood on a chair on the table && all the videos we watch that relate to physics. My quizzes are super junk so i gotta study more for them. And im thinking i should go in for extra during long homeroom. My goal is to not forget to turn in anymore homeworks and remember to take home my lab book so i can glue in my labs and finish them super good kine. My effort kind of got less and less and i still dont get the stuff were doing now. But ill go for extra help on monday in homeroom. Especially kuz my homerooms really close to class [haha].

This weekend i was at dinner at my grandmas house and trying to figure out what i was going to write my physics journal about when i realized i was sitting down and thats physics! I weigh 105 pounds so the force going down is 105 lbs. The chair counters my weight exactly so that i can sit. The force the chair exerts is called the normal. If the force i exert on the chair is too much the chair would collapse. My net force is 0 because the upward and downward forces are the same (equal). When all the forces are equal the object is in equilibrium. In this picture i am at equilibrium.

I'm a football manager/student trainer/watergirl and this friday as i was watching the game i realized that football is full of physics. When the quarterback throws the ball it's projectile motion. The projectile (the football) is going through 2 motions at once. It's going up & down (y)and from side to side (x). The football's y acceleration is always -9.8 m/s^2 because of gravity and its x acceleration in 0 (if there were no air resistance). The y velocity changes but the x velocity (ignoring air resistance) is constant. The x velocity has no effect of how long the football is in the air. The angle that the football is thrown in the air and y velocity determine how far it goes and how long it is in the air. In the picture to the left the word of life football player has been tackled and is falling at a rate of -9.8 m/s^2 and in the direction that hes being pulled down.

ohyeah & look at those cool girls in color :]

Yesterday i had a soccer game and i realized that kicking a soccer ball is related to a physics concept, Newton's first law of motion. Newton's first law of motion states that an object at rest stays at rest until an net external force acts upon it. It's also the same for an object in motion, the object will stay in motion moving at the same velocity until a net external force acts upon it. In this picture from last year's jv season im dribbling the ball propelling the ball forward. My foot acts as the net external force when i kick, trap, or redirect the ball. If i dont kick the ball it wont go anywhere and just stay at rest (0 m/s). If the ball is rolling (assuming no other net external force such as friction slows it down) it will keep rolling until i stop it.