The Top Ten...

Reasons Newton was a pretty cool dude.


Well this guy Newton taught us a lot of stuff, the most famous being his 3 laws. These laws, however, are the basic ideas behind some pretty fabulous inventions and concepts.






10. We can use Newton's nifty laws to determine the height of a building.

Yep, that's right.Newton’s second law states that force is directly proportional to acceleration and mass is inversely proportional to acceleration.

or...

 a=f/m

From Newton's Second Law we found our way to Free Fall. 

An object in free fall has a constant acceleration of 9.8 m/s^2 (or 10 as we used it). In our lab from Unit 2 we used this nifty number to calculate the height of third Anderson by dropping a ball multiple times from the third floor and taking the average time it took to reach the ground. We then used that average time and using the equation d=1/2gt^2 solved for the distance of the building. 

9. Newton saves our lives with airbags (in terms of momentum)! 

Newtons 3rd law states that for every action there is an equal but opposite reaction. This led into momentum.

Momentum=(mass)(velocity). 
Momentum=p. 
change in p= pfinal-pinitial. 
Impulse=J. J=F(change in t).
J=change in P. 

Momentum will be the same no matter what, so the impulse will be the same. Airbags increase the time impulse occurs, which means the force will be less (remember the big F and little t?). And a smaller force will lead to less of an injury!

8. Newton helps us flip!

Yep, that's right, all those gymnasts you see at the Olympics, they have one big guy to thank: NEWTON.

Newton's first law of motion talks a bit about inertia. It says: An object at rest remains at rest unless acted upon by a force. An object in motion remains in motion, and at a constant velocity, unless acted upon by a force.

Inertia is the tendency of an object to resist any change in its motion.

In Unit 5 Inertia took a different turn.  Rotational Inertia. w\Which is how much an object is willing to spin.

When gymnasts are flipping they tuck their arms close to their body, bringing their mass closer to center, decreasing their rotational inertia and making them spin fast enough to complete the turns.

7. Newton helps us play sports!

Rotational Inertia (which ties back into Newton's first law) can also help us run!

 Runners bend their knees when running because it lowers their center of gravity closer to the base of support making them harder to push down, and in a sports like Lacrosse or Football some contact is possible. Also, by bringing mass closer to the center of mass rotational inertia decreases meaning the ability to spin increases for when they need to be able to make those quick turns

6. Newton helped me make a mouse trap car!

Newton’s 1st Law- this is the law of inertia which states that an object at rest will remain at rest until a force acts to move it and an object in motion will stay in motion until a force acts to stop it. Our car wanted to stay moving so all we had to do to keep it that way was decrease the forces acting to stop it, such as friction.  

Newton’s 2nd Law- this is the law of acceleration which states that acceleration is equal to fnet over mass or a= fnet/m. By making our car lighter we could increase its acceleration because mass is inversely proportional to acceleration. Much the same way if we could increase the force we could also increase the acceleration.

 Newton’s 3rd Law- this is the law of action and reaction which states that for every action there as an equal but opposite reaction. By rotating our axle backwards and winding the string tighter we knew the car would rotate faster forwards.

5. Newton helps us measure force!

This guy Newton was so fabulous, he has his own system of measurement.

Force is measured in Newton's. 

But wait, just what is force you may ask? A force is a push or a pull that acts on an object.

Net Force: all forces acting on an object added together

Equilibrium: when an object is at rest or moving at a constant velocity, when all forces acting upon an object are equal and opposite.

4. Newton explains seat belts!

C'mon, we've all been there, asking why exactly we need those stretchy strips of material keeping us in our seats. 

Well, Newtons first law of motion states that an object in motion will remain in motion and an  object at rest will remain at rest until a force acts upon it. Therefore when a car stops and our bodies are moving forward they want to continue that way a seat belt keeps us from crashing through the windshield. 

3. Newton helps us pack!

Packing can be a hassle, especially when you have all those heavy boxes. Newton's second law helps us figure out how to move those gigantic bins of shoes and blazers.

For example:

If you were pushing an object with 200N of force and the acceleration was 2m/s^2, what would happen to the acceleration is your force increased to 300N? How do you know?

The acceleration would increase because force and acceleration are proportional as defined by Newton’s second law of motion which states that mass is inversely proportional to acceleration and force is proportional.

2. Newton keeps our muscles working!

Newton's third law states that for every action there is an equal and opposite reaction. 

So when we push on a wall or lift weights our muscles feel a force because the weights and the wall are exerting a force on them. The heavier the weight, the more force your muscles have to exert to make the forces equal and opposite.

1. Newton helps us make HOVERCRAFTS!!!!!!!!!!!!!!!!!!

You heard that right. HOVERCRAFT

 Newton's first law states that an object at rest will remain at rest unless acted on by an external force An object in motion continues in motion with the same speed and in the same direction unless acted upon by an external force.

Friction is tension between two objects that are touching. A hovercraft in motion will eventually come to rest because of friction and Newton 's First Law. 

Without Newton, we wouldn't have his first law, then we wouldn't have friction, and then we'd never stop moving!

So thanks Newton, for just being a generally cool dude!

El Fin

The first thing we hopped into with this unit (Unit 7) was magnets and magnetism.

Magnetism is pretty simple, the source of all magnetism is moving charges.

but it can still seem a bit abstract, let's use an example like... a paperclip!

But not just any paperclip, we want to make this paperclip magnetized. To do this we must first recognize clusters of atoms, known as DOMAINS. In your everyday paperclip the domains are unaligned, turning in different directions.

However, if you bring in another player, A MAGNET for example, these domains can be tamed. The magnet has a magnetic field. If we bring the paperclip close to the magnet the domains of the paperclip will align with the magnetic field of the magnet. The paper clip then has a north and south pole. The north pole of the paperclip will stick to the south pole of the magnet. Thus, they attract one another, and the paperclip itself is a magnet.

Wait, wait, wait, hold the phone. Like poles repel and opposite poles attract? How is that possible?

Magnets have both a north and a south pole. The magnetic field in a magnet runs down to the north pole, up, around, and down through the south pole. If you have a south pole of one magnet and the south pole of another magnet, they will repel each other. Like poles repel  because they are both pulling in. 

Then we rode our electron train all the way to Electromagnetic Induction.

Electromagnetic induction occurs when a magnet is moved through or over a coil of wire. This movement changes the magnetic field of the loop of wire, which, in turn,  induces a current.

So why exactly do we care about some current?

Well because it's how our credit cards work or course! And we all need those cute new shoes. In the credit card machine, there is a loop of wire. When the card, which has a strip of magnets, moves over the wire, it changes the magnetic field and induces a current. This current acts as a signal and tells the computer the information on your card. 

Electromagnetic induction also controls stop lights, metal detectors, and helps work your electric guitar.

KEEP ROCKING PHYSICISTS 

Then we rocked even harder. We road all the way into MOTORS!

By attaching two paperclips to a battery using a rubber-band you can create the base. You then attach a magnet to the top of the battery (get ready). Then coil some copper wire and (be) extra careful to not lose any limbs, shave off the tops of the sides of the wire so the current can travel. Then carefully place the coil in the paper clips and let it spin.

VOILA! You have yourself a motor. BUT WAIT. SERIOUSLY. How is this possible?

The battery produced electrons that flowed through the copper wire, which, in turn, reacted to the magnetic field surrounding the magnet

The paper clips acted as conductors and kept the coiled wire supported

The motor turned because the current carrying wire felt a force from the magnetic field

Oh hey look... it's me..

Transformers were the final thing we learned about. Transformers step-up or step-down voltage. They have a primary and secondary coil (Or a first and a second for those of us who don't like big words). In the primary and secondary coils the more loops of wire you have the more voltage is induced.  

But transformers are picky and only use AC current because without a change in the magnetic field, no voltage will be induced.




 :)   :)   :)

Believe it or not, I really enjoyed this unit. I felt like I learned the most about how the world works, and the practical applications of Physics in this unit. The building of the motor and the field trips to see the coils of wire in front of stop lights really made this unit seem important and relevant. 

My effort, for the most part, was steady. I feel apart with this final blog post (sorry Mrs. Lawrence, sorry physics people of the world). But I assure you it wasn't for lack of enjoyment. My attitude towards Physics remains positive and I have been pleasantly surprised by how much I have come to enjoy the class. 

I still can't really believe this is our last unit, it feels like only yesterday I was hating science and trying to avoid taking the dreaded Physics class. This Unit Blog post was a shaky end to what I believe has become a solid year of learning and improvement. I am proud of what I have learned this year and hope you (yes even you readers who have no idea why I'm putting all of this on a blog) can see that!