Relationship Between Work, Energy, and Power

Power is the rate at which work is done and to do work you require energy.

P = E (Joules)
      -----------
       t (time)

W= FD ( force x distance)

Suppose there is a force  F acting on an object, causing it to move in a particular direction. Then the work done by the force is the component of F in the direction of motion × the distance the object moves as a result. Work done is measured in joules (J). 

However, if this force is at an angle of a to the horizontal and the body moves a distance of s metres along the ground, then the work done is F cosa × s (since F cosa is the component of the force in the direction of motion).

** If energy is conserved, no work is done. if it is not conserved, it is used to do work.

There are two main types of energy: kinetic and potential

The kinetic energy (K.E.) of a body is the energy an object has as a result of its motion. An object which has no motion will have zero kinetic energy, therefore.

                          K.E. = ½ mv²
   where m is the mass and v is the velocity

Potential energy (P.E.) is the energy an object using height to its advantage

                         G.P.E. = mgh
where h is the height of the body above the ground.

Basically, the total potential energy measures the energy of the body due to its position.

All three variables are dependent on one another and if one was missing, the others wouldnt exist.

Ready, Set, Fire!!!

From watching many movies of the past, we have observed a weird device when loaded with gunpowder would shoot up and cause objects at far distance to explode. KABOOOMMM.. Now what is this device called?  Wait, wait! I'll tell you ;) : a cannon. A cannon is any piece of artillery that uses gunpowder or other usually explosive-based propellants to launch a projectile. They were very popular weapons in the 18th and 19th centuries. However we have newer technology which can also be referred to as cannons today such as guns, howitzers, mortars, etc.. One of the tips to making a successful cannon is following the general rule which is the longer the barrel, the longer the range of the cannon. To shoot the cannonballs to a great distance, large amounts of gun powder would be required as well. The Tsar Cannon is the largest Howitzer made weighing at 39.312 tonnes and has a length of 5.34 m

A view of the Tsar Pushka, showing its massive bore and cannonballs,
 and the Lion's head cast into the carriage.

Results from Newton's Lab... who says getting hit in the head can't help you?

After a long time I was able to have fun with pulleys and loads. We were to differentiate between mass and force with acceleration. There were 5 different cases we were to follow and produce results. These are the results that I collected with my group :) 

Data collected from the 5 cases

The tower is falling down... falling down

So last week we did another fun activity: constructing a tower. I should mention its not as easy as it sounds with limited tape and newspaper, yet again. That was all we received with even less time! My group and I started with cylinders for the base and for the top we rolled the rest of the papers and stuck it on the top. However, the top was ending up with more weight. Thus, it kept bending :(  We tried repeatedly to fix the problem but it's not like we had any more materials to strengthen the base. Then out came Mr.Chung and said time out. We tried to improve it even after time was up :P well until Mr.Chung was judging our (if you can even call it that) tower... So now it is evident that we were unsuccessful. But all creators fail at some point or the other right? I take this in the positive way and I know what I would have to do to produce better results next time :)

How it all started...

so yeah it won't stay down :P

How High Can You Go?

Ever wondered if there are structures taller than our own CN Tower? Well in reality the CN tower is ranked around the 100's for tallest structure. At number 1 we have Burj Khalifa with an enormous height of 828 m (2717 ft.) What has enabled this structure to maintain such a grand height? Usually when designing a building the main considerations to create a successful building is:

1. The use of strong, unbreakable materials
2. The shape. Usually we see buildings decrease in width from top to bottom. This increases stability. Of course we can't forget the triangles. It had been put into our heads since grade two that it is the strongest shape out there!
3.Weight can be another factor. We can't have a heavier top than bottom... The base should have the most mass.
4. Having a low centre of gravity which minimizes risks and difficulties

Burj Khalifa - Tallest Structure in the World!

What Goes Up Must Come Down!

   We have now started a new section in our unit in kinematics : projectile motion. It seems very complicated at first but eventually you get the hang of it. These are the answers from 1-9 in the projectile motion worksheet.

Egglander or Egg Failure?

Today we were given a new project which would begin on wednesday; it is a gliding egg lander. Let's start by defining aerodynamics. It is the study of forces and the resulting motion of objects through the air. Now what does this have to do with eggs? Well as I mentioned, the egg does have to somewhat fly and to be successful in doing so, we have to know some information about aerodynamics: the study of air and its motion. For this project we will be given 25 straws, one sheet of newspaper, and a limited amount of tape. Learning that was all we had to work with, my group and I got really depressed. However, as Mr.Chung always says: never get freaked out by problems; just slowly and intelligently work it out (changed into my own words of course haha)... To do well on this project, the best thing would be to determine what kind of shape we should use to protect the egg. Obviously the first thing that came into my mind is the structure of a hang glider. Therefore to make our egg glide well enough, making wings for it would be a good idea and making a cushion is good for a safe landing. More brainstorming will be needed evidently but hopefully we can make a good egglander :)

A design I liked made by well some kids in college :P

A design of a hang glider