Physics according to David: November 2014

Tuesday, November 18, 2014

Tides

This is an extreme example of tides called a Bore tide. This takes place in Alaska and is such a unique tide that it creates a visible wave that can even be rode into shore.

This is not by any means a normal tide. But what are tides and why do we have them?
Tides are the movement of the oceans water in a rising and falling pattern. The tides are caused n the difference of forces between opposite sides of the earth relative to the moon's gravitational pull.
The difference in the forces is caused by the distance from one side of the earth to the other. what this causes is tidal bulges that form on the sides closest and furthest from the moon, and leave the sides in the middle with the most average tide. When the moon is either lined up directly with the sun or is directly opposite the sun relative to earth we get what is called spring tides. when the moon is and a ninety degree angle to the earth and sun, we experience neap tides.

This is the tide chart for Panama City, Florida.

Right now, the beach is at a low tide

Panama City, St. Andrew Bay, Florida
30.1517° N, 85.6667° W

2014-11-17  6:09 AM CST   Sunrise
2014-11-17 10:45 AM CST   0.57 feet  Low Tide
2014-11-17  4:45 PM CST   Sunset
2014-11-17  7:58 PM CST   0.94 feet  High Tide
2014-11-18  5:48 AM CST   0.44 feet  Low Tide
2014-11-18  6:10 AM CST   Sunrise
2014-11-18  4:44 PM CST   Sunset
2014-11-18  7:54 PM CST   1.08 feet  High Tide
2014-11-19  5:59 AM CST   0.27 feet  Low Tide
2014-11-19  6:11 AM CST   Sunrise
2014-11-19  4:44 PM CST   Sunset
2014-11-19  8:08 PM CST   1.21 feet  High Tide
2014-11-20  6:12 AM CST   Sunrise
2014-11-20  6:28 AM CST   0.10 feet  Low Tide
2014-11-20  4:44 PM CST   Sunset
2014-11-20  8:33 PM CST   1.35 feet  High Tide
2014-11-21  6:13 AM CST   Sunrise

Currently the Beach is experiencing Spring tides.

Moon: 16.0%

Waning Crescent

Current Time:Nov 18, 2014 at 8:27:44 AM

Moon Direction:↑ 148.63° SSE

Moon Altitude:72.51°

Moon Distance:246768 mi

Next New Moon:Nov 22, 20147:33 AM

Next Full Moon:Dec 6, 20147:27 AM

Next Moonset:Today3:08 PM

Saturday, November 8, 2014

Unit 2

During this second unit, we continued to discuss, learn about and base our work on the laws of Sir Issac Newton. The law that we learned about and worked on during this unit was Newton's second law.

Newtons second law states that: Acceleration is directly proportional to force, and acceleration is inversely proportional to mass. What this looks like as a formula is
a = F x 1/m or a = F/m
a = acceleration F = force m = mass
When we say that acceleration is directly proportional to force, what that means is that as an objects acceleration increases so to does the objects force. And as the objects acceleration decreases so to does the objects force decrease.
acceleration (increase) = Force (increase) acceleration (decrease) = Force (decrease)

The other portion of the law says that acceleration is inversely proportional to mass. What this means is that as the mass of an object increases the acceleration of the object will decrease. And as the mass of the object decreases the acceleration of the object will increase.
mass (increase) = acceleration (decrease) mass (decrease) = acceleration (increase)

We tested this law with an experiment in class using a rolling cart, and hanging weight, and changing the locations of the mass of the system, and recorded the changes in the acceleration of the system. Notice how I said that we changed the locations of the mass of the system? This is important to note because throughout the experiment we were moving weights around to different locations on the system, but the net weight of the system remained the same throughout.

[ ] = = = &
cart^ weights^ hanging weight^

for the first run we had all of the weights on the cart and none on the hanging weight. This resulted in a minimal acceleration because the mass of the cart was great, and Newton's third law tells us that mass and acceleration are inversely proportional.
run 1.) [===]-------
&
For the second run we placed one of the weights on the hanging weight. What this caused was a greater acceleration than in the previous run. This is because the the net weight of the system remained constant but the location of the weights caused the hanging weight to accelerate more than the time before resulting in a greater acceleration of the cart.
run 2.) [== ]------
=
&
Runs 3 and 4 also saw that the cart's acceleration continued to become greater every time the weights were transferred to the hanging weight.
run.3.) [ = ]------
==
&
run 4.) [ ]------
===
&

Next is the concept of free fall. In Free fall:
* the acceleration is 9.8m/s^2 in real life, or 10m/s^2 in the lab. what this means is that the object that is experiencing free fall will accelerate 9.8m/s^2 faster that it was the second before.

Similar to free fall, falling through the air also has an acceleration of 9.8m/s^2. However in falling through the air the object is subjected to air resistance. What this air resistance produces is something called a terminal velocity.

* Terminal Velocity is when an object is falling at the fastest speed possible and has an Fnet of 0 meaning that the force of gravity pulling the object down is equal to the force of air resistance against the object. The amount of air resistance on an object depends on the mass, surface area, and speed of the object. If any one of those variables changes, then the object's speed will have to adjust to the new terminal velocity.

When throwing things at an angle, the only thing that determines the hang time of the object is the vertical distance. and to find this vertical distance we use the formula
d=1/2g(t)^2

Friday, November 7, 2014

I really liked this video because it helped me understand Newton's Third law in the context of football. I had actually been struggling with the concept in this setting and this video cleared many things up.

And FOOTBALL I mean, c'mon......