Types of Energy!

If you want to do work, you have to have energy, otherwise nothing will ever get done. Energy is what keeps us moving through the day. There isn't, however, only one type of energy. Energy can come in many different forms and each has a specific function.

Sound Energy: Sound energy is the energy produced by sound vibrations as they travel through a specific medium. Sound vibrations cause waves of pressure which lead to some level of compression and rarefaction in the mediums through which the sound waves travel. In other words, sound energy is a form of mechanical energy.
Mechanical kinetic energy: Mechanical energy is the sum of energy in a mechanical system. This energy includes both kinetic and potential energy. In a mechanical system, gravity is the outside force needing to be considered, and in a chemical system, the forces between individual molecules and atoms must all be considered.

Thermal (heat) energy: Thermal energy is the vibration of atoms and molecules of a substance. As an object is cooled down, the atoms move slower, and as it is heated up, the molecules move faster.

Chemical potential energy: When there is a storage of food and fuel into work. Potential means that there is a tendency to do work, but work is not being done in that particular moment. Chemical means that when an object is changed chemically. For example, when sugar is put into water, it is chemically changed.

Elastic potential energy: From the previous knowledge we have on potential energy, we should move on to elastic energy. As you are aware, elastic is something that can 'spring' or 'elasticity'. This helps lengthen the distance an object can travel.

Gravitational potential energy: Gravitational potential energy is exactly what it sounds like. So having potential energy means that an object has the potential to convert different types of energy to another type of energy. And gravitational energy is associated with gravity. Gravity is the Earth's pull downwards that affects every single object and being on this Earth. When there is a force of gravity acting upon something, it means that that object is being pulled to the ground, thus having a gravitational energy acting on it.


These are all the different types of energy that we need to be familiar with. There are many more types of energy but for now, these are the ones we need to know!

-Peggy.

Cannons!

Yesterday in class we were given a new task: to build a cannon out of five pop cans and a ball made out of two Styrofoam cups held together with duct tape, and hope for it to go the furthest it can. We will be using ethanol as the liquid inside, and will light it up with a match. The objective of this assignment is to make the ball shoot the furthest, or at the least leave the cannon, and the creativity of the design. This will be done in groups of four, preferably your roller coaster group, but if not, then a group of your own. We will have the whole period on Thursday to build our design, and we will be shooting our cannons on Monday. Remember, you only get ONE try, so use it wisely!

With a little research online, you can find a clever and efficient way to build a cannon that will meet the requirements of the assignment, it is fairly simple to make in an hour, and can shoot the furthest. If you are able to cover all three of these areas, you will receive a satisfying mark.
In order to make a successful cannon, the launcher itself needs to be long so that the ball can travel inside it. Yo then need to connect the pop cans with duct tape, so that nothing leeks, and make a base, with your creativity.
Here is a link I found that shows how to make a cannon with five pop cans. In this video, they do not have a base, but it is easy to make one. However, the trick is to get the angle correct as to increase the flying distance of the ball!
Check it out!!!!!

http://www.metacafe.com/watch/1006657/can_canon_with_soda_cans/


JUST FOR FUN!
Here is a video I found that shows how to make a potato cannon. It seems pretty intense and I enjoyed watching it, so if your interested, take a look. =)

http://www.metacafe.com/watch/699080/how_to_make_a_potato_canon/

-Peggy.

Inclines and Pulleys and Trains Oh My! Plus Equilibrium!

Another unit has ended and a new one has begun. Yes, after the painful kinematics test we wrote last week, we moved onto a new chapter in our fascinating physics textbook, NEWTONS! I must admit, Newtons is not easy, but it is interesting. If you know what you are doing, then it is a guaranteed A on the test and of course, exam. However, for ones who try to escape math as much as possible and find it hard to do math, like myself, need to work hard to try and understand the problems. There are only four different problems we are learning to solve in this chapter, and they are: equilibrium problems, inclines, pulleys and trains. They sound easy, no? Well what can I say. They are okay but they require a big chunk of your time, energy and brain to wrap your head around them.

Before I start, you need to know Newton's three rules.
Newton's first law, law of inertia, states: '' all objects will remain in a state of rest or continue to move with a constant velocity unless acted upon by an unbalanced force.''
Newton's second law states: '' the acceleration of an object depends inversely on its mass and directly on the unbalanced force applied to it.''
Newton's third law states: ''for every action force, there is an equal and opposite reaction force.''
Once you are familiar with these concepts, you can apply them to solve the four problems: equilibrium, incline, pulleys and trains.

EQUILIBRIUM: when all forces are balanced









INCLINE: Friction, Static




Friction:






Static:





PULLEYS:








TRAINS:






NOTE: For every problem, do not forget to draw the FREE BODY DIAGRAM, otherwise you will lose marks, and it might be more difficult to do the equations!

-Peggy.

Survival of the EGGS!

Humpty Dumpty's journey was very exciting and exhilarating for the past few days. I must inform you though that Humpty Dumpty is my group's egg in which we had to help survive a one story fall. We all had the task of having to build a cage made purely out of 25 straws and limited tape. We also had to make the cage in a way in which we could easily take the egg out if needed. We also could not do anything to our egg, like boil it or put tape on it or any other clever thing that comes to mind. On the day of the drop, Humpty Dumpty was very excited yet quit nervous too. He was unsure of the structure we had built for him and was terrified to even think that his short life may come to an abrupt end, with one bad stunt. Of course, being the hero he is, he had faith in our ability to keep him alive. With his belief and loyalty to the group, he agreed to experience this one story fall. As we anxiously waited at the bottom of the wall in which Humpty Dumpty would be dropped from, we wished him the best of luck. Here is what Humpty Dumpty's fall looked like in a snap shot.

When Humpty Dumpty landed, my group members and I took a picture of our beloved egg. Can you guess if Humpty Dumpty survived his fall or not?




By now your probably know that Humpty Dumpty's fall was SUCCESSFUL! He enjoyed his fall very much, and thanked us for letting him live another day. All thanks to our brilliant engineer minds, we were able to save an egg from cracking! Here is a picture of Humpty Dumpty's landing.




Until next time,
Bye!

-Peggy.

How does the marble drop?

What is the difference between holding a paper ball in your hand and dropping it into a container while walking versus running towards the container and dropping the ball in hopes of it landing in the container? Well, we you are walking and you drop the ball, the ball generally falls in a vertical motion, considering of course that there is no wind. However, when you run and drop the ball, the path of the ball will be curved. This is called a projectile. There are four types of projectiles.

Here is an example to help you grasp the concept better.

Example #1

Hope this clears up everything.
Thanks,

-Peggy.

Rollercoaster; which is your fav?

When you go to an amusement park such as Canada's Wonderland, what is the first roller coaster you rush to? Your absolute favourite ride in the whole park. Well, my favourite roller coaster is Behemoth. I just love the idea of a really big and fast roller coaster. Although I would have loved it even more if it had loops in it, but because of the way it is built, having loops would be dangerous and impossible. Some are terrified of roller coasters, and some enjoy them very much, but has anyone ever stooped and thought how a roller coaster really functions? Well, since we are required to build a roller coaster in class, we must first think of the physics side of the matter, and then the entertainment part. Knowing Newton's laws are essential in building a roller coaster.
Newton's first law, law of inertia, states: '' all objects will remain in a state of rest or continue to move with a constant velocity unless acted upon by an unbalanced force.''
Newton's second law states: '' the acceleration of an object depends inversely on its mass and directly on the unbalanced force applied to it.''
Newton's third law states: ''for every action force, there is an equal and opposite reaction force.''
Using these laws, we can conclude that when the roller coaster is being pulled up the track with a chain, Newton's first law applies. When the roller coaster is in motion, from the second it is in free fall until it comes to a stop, the weight of the riders and the actual ride will impact its acceleration, which is Newton's second law. And the third law is displayed when the roller coaster is going up and against gravity, it eventually has to come down, towards it.
This goes to show that the saying ''what goes up must come down'' is a very true statement indeed.

-Peggy.

Who knows how to add vectors?

Hello there. This week in class we have been learning how to add vectors, and let me tell you, its actually not that hard once you get your head wrapped around the concept and you do a lot of questions. Here is a question that was on the green sheet Mr. Chung gave us.

A+D
The first thing you do is to draw the direction of the positive arrows. It should look like this.

Then you need to figure out the values for x and y of the diagonals.
Ax+Ay+Dx+Dy
= Ax+Dx + Ay+Dy
= 11.5km[E] + 18km[W] + 9.6km[S] + 1.6km[N]
11.5 and 18 represent Rx and 9.6 and 1.6 represent Ry
A simple way to add these together is to add the directions opposite of each other together. First you have to turn them into one unit. For example, going a certain distance towards North is the equivalent of going that same distance South, because they will cancel each other out. The same with going a certain distance East and going back the same distance West. In this case, if you want to add 11.5km[E] + 18km[W] , you need to subtract 18km[W] from 11.5km[E] and keep the [W] sign.
The answer would be Rx= 6.5km[W].
You could also subtract the East direction from the West, but then would have to keep the East sign.
Similarly, you would do the same for North and South.
9.6km[S] + 1.6km[N]
= 1.6km[N] - 9.6km[S]
= -8
Ry= 8km[S]
(Keep in mind that the negative sign does not change the number, it simply shows the direction. If it is negative, it means it is going in the opposite direction)

You then use the Pythagorean theorem to find the hypotenuse:
R=
R= 10.3

Lastly, you use trigonometry to find the angle.
tanθ =opp/adj
= 6.5/8
θ= tan -1 (6.5/8)
θ = 39˚

You now have all the missing pieces, and need to simply put them together.
R= 10.3 [S 39˚ W]

Here is what the triangle would look like.



-Peggy.