Friday, May 23, 2014

Top Ten Applications of Physics

10.  The number tenth application for physics is using it to find out the gravitational potential energy of an object, using the formula PE=mass times gravity times height.  You can use this to figure out how hard something will hit the ground when dropped from a certain height.
9. The number ninth application for physics in the real world is determining the kinetic energy of an object with the formula KE=1/2mv squared.  You can use this to figure out the force something is going to hit you with, or how much energy an object has while it is moving.
8. The eighth application for physics in real life is determining the rotational velocity of a wheel.
The rotational velocity is how many rotations per second a wheel goes, and this is used for things like figuring out how fast a car is moving.
7.  Number seven is using torque.  Torque is Force times a Lever arm, and it is used to leverage your strength to do things that you normally couldn't, such as turning a really stubborn bolt, or cutting through steel with a really big pair of scissors.
6.  Number six, Gravity.  The way to find out the gravatic attraction is between two objects is:
Gravity= g(m1 times m2)/d^2.  We use this to figure out how much attraction is between satellites and earth, and gravity itself binds the universe together.
5.  Number 5 is centripetal force.  Centripetal force is the thing that causes you to be forced up against the side of a car that is spinning in circles.  You use it every time you wash your clothes, because the spinning motion of the washing machine causes the water to force itself out of the turbine, letting your clothes get spun dry(er).
4.  Electricity!  Without electricity we would not have any of our wonderful technology that we use today.  Electricity is a current, and current is voltage/resistance, which is shown by Ohm's law.
3. Circuits are methods of moving electricity from one place to another.  They have to be a completed loop, and you can turn the flow of electricity on and off by breaking the circuit.
2. Magnetism.  Magnetism is a product of aligned domains in ferromagnetic materials.  Domains get aligned when either subjected to an aligned magnetic field, or getting hit with something while exposed to a very weak magnetic field (such as the Earth's field).
1.  Number one is generators.  Generators are ways of producing electricity by moving a magnet across coils of conductive wire.  You input force, and out comes electricity.  This is the best way to produce electricity.

Wednesday, May 21, 2014

Wind Turbine Blog

Me and Manuel constructed our wind turbine using several pieces of PVC pipe, and well as a plastic dustpan and the magnets and copper wire that were used to make the generator.  What we did was that we used the PVC pipe to make the housing of the wind turbine, and cut the dustpan into a pinwheel design, in order to catch the wind more effectively.  Inside the housing, we attached four coils of wire on the interior of the pipe, and to the turbine shaft we attacked four magnets.  As the turbine spun, the magnets would spin over the coils, generating electricity.

Monday, May 12, 2014

Blog Reflection 5-12

In this unit we studied electricity and magnetism, as well as practical applications of each.  We learned about the directions of magnetic fields, and about how the field flows from the north pole of the magnet to the south pole of the magnet, and about why the like poles repel each other, while opposite poles are attracted to each other.  We also built an electric motor, made out of a magnet, a battery, a coil of copper wire and a paperclip.  A motor is like the reverse of a generator, in that a motor takes electrical power and generates force, while a generator takes force and uses it to move a turbine to generate electrical power.  Certain electric cars can convert their motors to generators when they are coasting.  We also learned about transformers, and about how they only work with alternating current and not direct current.  The equation to find the change in voltage from primary to secondary, (input to output) is Vp/Tp = Vs/Ts where V is voltage and T is turns.  we also learned about how magnets generate a magnetic field due to the fact that they have aligned domains, which are groups of electrons and that any ferrous metal exposed to a magnetic field will start to generate an identical magnetic field of it's own.  This includes nails exposed to the earths magnetic field and hit with a hammer.
        I had no particular difficulties with this chapter, but once again, the formulas were troublesome.