Momentum and Impact
This week in Physics, we learned about momentum and impact.  The Law of Conservation of momentum states that in an isolated system momentum will be conserved.  Momentum is measured in kg • m/s and can be found using the formula P=m • v (P=momentum, m=mass, and v=velocity).  In the picture below, the momentum of the wave carries the surfer along its face.  This momentum transfers to the surfer allowing him to move with the wave.  This momentum can be manipulated by the surfer allowing him to perform maneuvers.  Momentum in = momentum out.

We also learned about impact.  Shorter impact time = greater impulse.  Longer impact time = less impulse.  In the water balloon toss activity the balloon broke when it hit the ground because of its short impact time.  When the sheet caught the balloon it did not break because it increased its impact time.

Forces That Accelerate
This week, we learned more about Newton's Laws of motion.  More specifically, acceleration and Newton's second law.  Newton's second law states, 'the acceleration of an object is directly proportional to a net force on an object and the acceleration of an object is inversely proportional to the object's mass.  From this law, we learn that acceleration is directly proportional to the Fnet (sum of all forces), and that acceleration goes down as the mass of an object goes up (vice versa).  This is represented by the equation a=Fnet/mass.
Fnet can be found by the equation Fnet=m•a.  (m = mass, a = acceleration)

A force that accelerates is a skater.  While cruising around my neighborhood, I noticed that I was accelerating with every push I took. I realized that as i pushed on the ground, the ground pushed me back and accelerated me forward.

And Fight Club was a very good movie.

Newton's First Law
This week in Physics, we learned about Newton's laws.  His first law titled, "Law of Inertia", states that objects in motion (or at rest) will tend to stay in motion (or at rest) unless acted upon by an outside, unbalanced force.  For example, a ball at rest wants to stay at rest and only moves when it is kicked or thrown.  In this case, the outside, unbalanced force is the person kicking or throwing the ball.

This bunch of bananas are a perfect example of Newton's first law.  They are at rest therefore they want to stay at rest.  The only way they would move is if they were moved by an outside, unbalanced force which would be someone grabbing them.

Projectiles (Part II)
A projectile is any object moving through the air where the only force acting upon it is gravity.  As the projectile is thrown into the air at its given initial velocity, it accelerates at a rate of -9.8m/s^2 in the y-direction.  Meaning it moves in a fast-slow-stop-slow-fast motion pattern.  However, on the x-axis it moves at a constant speed.  This unique combination causes the projectile to move in a parabolic motion.
During physics this week, we practiced finding unknown values dealing with projectiles.  Initial velocity, range of the y and x axis, and time of flight were just a few we were able to find.  Physics also allowed us to predict the landing of a silver ball given its velocity, height, and acceleration.

The picture of the skater below is a projectile.  His motion in the x-axis is constant whereas he is accelerating at -9.8m/s^2 in the y-axis.