June 29, 2012

Today was a really productive day for the entire class filled with excitement and fun.
First, we started off the day by reviewing and then taking the semester one final exam.

 After we came back from lunch, we competed in the mouse cart competition, which was won by Nicole and Chelsea.

Finally, to end the day, we performed our lab on the functions of all of our mouse trap cars.
 
Real world connection:
Many people these days own trampolines. However, many do not understand the physics behind them. They use a form of elastic potential energy in order to function. The harder you push down on the trampoline with your body, the higher you will jump.

June 27, 2012

Today we learned about the difference between the forces of static and kinetic friction:
The force of static friction is the force required to begin movement
The force of kinetic friction is the force required to keep the object moving



Through our experimentation with the friction lab, we discovered two new equations related to the standard y = mx+b:
F[s] = Mu[s] x F[N] and F[k] = Mu[k] x F[N]


To finish off the day, we received two packets of problems, one for these two new equations that we learned along with all three of Newton's laws, and another one to help us review for the final.
 
Real world connection:
With the olympics coming up, figure skating is deifinitely entertaining to watch. But, their speed is what makes it so awe-inspiring. The reason that they can go so fast is because their kinetic friction between the ice and their skate is little to none. As a result, they have the ability to travel much faster compared to being on the ground

June 26, 2012

Today, we began the day off with an introduction to the concept of normal force:
- Contact force
- Perpendicular
- Not always upwards
- Adjusts

Next, we learned about  interaction diagrams and free body diagrams, which are both ways to accurately measure forces between different objects.

        

In addition, our lab today consisted of using interaction diagrams and free body diagrams to calculate the proportions of force between the different ways that our soccer ball hover cart moved. For example, we saw that the force of gravity on Earth is always acting on both person one, person two, and on the hover cart.

June 25, 2012

Today, we began the day with the Newtonian Analysis of motion and the PGA:

1. Engage in force analysis - add forces acting in same direction, subtract forces acting in opp. direction
2. Find net force
3. This F[net] leads to accelerations

*Forces are vectors: + right/up, - left/down

After the break, we went onto the fan cart lab in which we examined the relationship between force, mass, and acceleration.
We derived an equation that related all three together: F = ma where as the mass increased, the acceleration decreased, and the force stayed constant.


Newton's 1st law:
Forces are balanced - v=0m/s^2 obj at rest, a = 0m/s^2, stays at rest
                                - v doesnt = 0 obj in motion, same speed, same direction

Newton's 2nd Law
Forces are unbalanced - there is acceleration - acc proportional to force
                                   - acc inversely proportional to mass

Big Ideas:
- To keep moving @ the same speed in the same direction, you dont need any force (Net)
-F(net) = Ma
- F(net) = M x (change in v/change in t)
-Force(net) required Change in V

June 22, 2012

Today, we began class with the postgame analysis where we took several steps to find the various characteristics of a velocity vs. time graph.
- If signs of velocity and acceleration are the same: then the object is speeding up
- If signs of velocity and acceleration are different: then the object is slowing down

Then, we performed the Motion Analysis: Falling Objects lab in which we dropped blocks of wood with different masses, and measured their slopes using video analysis to determine acceleration due to gravity.

Afterwards, we had our kinematics test in which we had to apply all of the new equations we learned yesterday.
Next, we were introduced to the KOTH project:

Lastly, we finished off the day by watching an installment of Elegant Universe

Real World Connection:
Mouse traps are set by pulling back the lever, which gives it a ton of potential energy. When the trap is triggered by an object putting weight on it, all that potential energy turns into kinetic energy which has the power to easily kill a mouse.

June 21, 2012

Today was basically the opposite of yesterday in which we had a lot of material to catch up on.
To begin the day, we had our postgame analysis:

3 big ideas:
1. Acceleration (m/s[squared]) = change in velocity/change in time
2. In a position vs. time graph, slope = velocity aka change in position/change in time
3. ***In a velocity vs. time graph, the slope = acceleration; the area = change in x - total distance travelled

3 BIG EQUATIONS: y=mx+b
1. x[f] = vt + x[i]
2. v = at + v[i]
3. x[f] - x[i] = vt + 1/2a[t^2]
Then, we moved on to the motion analysis lab in which we saw acceleration, velocity, and position are all interconnected by capturing slow motion video of our cart accelerating, then decelerating on the ramp.

Next, we received some new intersting kinematics problems where we applied our newly learned equations and whiteboarded our individual problems.
Lastly, to end the day on a quiet note, we took the time to reassess at most 4 standards from the collisions test taken yesterday. Personally, I only chose to reassess 3.1.
Real world connection:
Cars are a perfect example of how velocity, acceleration, and position are all connected. The acceleration of a car is determined by how fast it can become within a certain amount of time. As a result, the word acceleration is tossed around much more frequently in the world of cars compared to velocity.

June 20, 2012

Today in class, we began by learning 3 new types of charts/graphs: the LOL graph, the IF graph, and a third graph that shows the reactions between the two carts stuck together at rest, and then explode. Respectively, the first two graphs are of energy transfer and storage and of momentum transference. Personally, I enjoyed the LOL graph the best because it seemed to appear the mot clear to me.

Next, we had our postgame analysis:
1. Impulse (change in P) should be equal and opposite for the red & blue cart.
2. Total impulse for the whole system = 0
3. Total momentum before = total momentum after
-Ft = +Ft

 http://www.youtube.com/watch?v=y2Gb4NIv0Xg - here is a good link on momentum and its characteristics.

Real world connection:
If two kids are playing with remote controlled cars one day and decide to see what happens when they drive them at each other, they would see that momentum would remain consistent throughout the collision. Moreover, if they calculated the impulse of their activity, it would turn out to be zero because in any sort of collision, the impulse always adds up to 0.

June 19, 2012

Today in class, we began with our daily ipad activities followed by the postgame review:

1. Scalar quantity (magnitude) - mass(kg) & energy(J) vs. vector quantity (magnitude + direction) aka velocity & momentum
+ = right/up, - = down/left

2. collisions A. sketch; B. analyze; C. Scalar: KE=1/2mv(squared); vector: P = mv

3. %lost = total after - total before/total before

Big Ideas:
Elastic collisions conserve more Energy than inelastic collisions
Momentum is conserved in all collisions (total P before = total P after)
Momentum is the best way of analyzing collisions

Impulse
J = P(final) - P (initial)

impulse should be equal + opposite
momentum total  - same before + after
any lost by one cart should be gained by another
impulse = this gain or loss
impulse for whole system = 0

conservation of momentum:
-any gain in momentum ...something else must lose momentum in a system

Real world connection:
If a clumsy student were to drop a textbook and a basketball out a window, he would see that they each had the same momentum right before they hit the ground. In addition, he would observe that the basketball had a greater impulse because its change in momentum is higher due to its elasticity.

June 18, 2012

Today, we began class by recapping week 1 with this picture:
After the break, we came back to do a little peer teaching before taking the Energy Conservation Lab and Practical Test, which took us into lunch until noon.

After lunch, we came back to perform the collisions lab and to learn several new terms.
Energy lost: (energy before-energy after)/energy before x 100
Scalar: simply valuies; no direction involved
velocity: magnitude and direction
Anything moving right or up = positive
Anything moving left or down = negative
Elastic collision - bounce, conserves mechanical energy
Inelastic collision - thud, some ME is converted to internal energy
Momentum(P) - mass x velocity (kg x m/s)
During the lab, we noticed that elastic collisions were more efficient at conserving mechanical energy than inelastic collisions

Real world connection:
When scientists collide particles to try to recreate the Big Bang, they are using these very laws of energy conservation and collisions. They shoot particles with extremely high velocities at each other in hopes to create the conditions that caused the big bang. Rather than bounce, these collisions cause conditions for a fraction of a second, which can give clues to the origins of life on the planet.

June 14, 2012

Today in class we first went over the postgame review of what we did yesterday.1. Mass=kg, force=newtons, gravity=N/kg (10 on earth), work=joules, distance=meters2. Force - Push or pull3. Energy - The ability to do work4. The force of gravity = weight5. work = energy EquationsF = mg(force = mass x gravity) w = Fd(Joules = N x meters)

 Next, we did the pyramid lab with our new groups. In this lab, we experimented with how the steepness of a ramp affects the force needed to move a weighted car over a certain distance. Just as we learned yesterday, as the distance from the car to the destination decreased, the force needed to move it to that point increased. In addition, just as predicted, the areas of each graph was approximately the same.

Lastly, we took our test on simple machines to finish off the day. Real world connections:​Simple machines such as levers and ramps have infinite uses in the real world. For example, in order for the ancient Mesopotamians to build their buildings out of mud and clay bricks, they needed to use levers to life these materials up, and they needed ramps to move the bricks up towards tall buildings. Also, they needed to use levers to move heavy rocks out of the way to make space for building projects.

June 15, 2012

Today, we continued our study of the transfering of energy.
1. Work = Force over distance
2. Heat = molecules colliding
3. Radiation = light waves
Energy always transfered from high--->low, E---->E
Potential Energy(gravity) - position
Potential Energy(elastic) - position
Kinetic Energy - motion
All three of the above types of energy: Mechanical energy - Any energy due to position or motion
Next, we experimented with the potential energy that rubberbands have, the force required to pull them, and the velocity of carts that are pulled and released against them.
We discovered that as the rubberbands were doubled and pulled back farther, their potential energy increased, thus causing higher outputs of energy with objects such as the carts.
In addition, we learned several new equations through our study of energy conservation:
PE(gravity) = (mass)(gravity)(height)
PE (elastic) = 1/2(elastic constant)(distance stretched squared)
KE = 1/2(mass)(velocity squared)
ME = PE x KE
Lastly, we had our postgame review:
1. E(trransformed) - work, heat, and radiation
2. E(stored) - PE(gravity), PE (elastic), kinetic energy
All three are of mechanical energy
3. Mechanical energy = position or motion
Real World Connection:
When buildings are being demolished, construction workers use machines to help tear them down.
For example, cranes use the position of their wrecking balls to destroy buildings due to their stored potential energy. By holding the wrecking ball in a high position and then letting it fall, enough energy is released to break down walls.

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