state of equilibrium

                                                                                   

We did a lab report during the last semester talking about the equilibrium force on the force table which calculate the equal force in different angles.

When all the forces that act upon an object are balanced, then the object is said to be in a state of equilibrium. The forces are considered to be balanced if the rightward forces are balanced by the leftward forces and the upward forces are balanced by the downward forces. If an object is at equilibrium, then the forces are balanced. Balanced is the key word that is used to describe equilibrium situations. Thus, the net force is zero and the acceleration is 0 m/s/s. Objects at equilibrium must have an acceleration of 0 m/s/s. This extends from Newton's first law of motion.

The important rule to make a great bridge which can afford huge weight is separate the force to all parts of the bridge, so the angles and arch can help with this problem.

http://www.physicsclassroom.com/class/vectors/u3l3c.cfm

About my new born bridge

I didn't start to build my bridge yet but I'm going to build a bridge like this

Triangle is stable and easy to build, this  makes me want to build this one rather that an arch one.

A little bit Bridges!!!!

This Picture is a great explanation about all kinds of bridges, but it doesn't mention where to use those kinds of bridges.

Truss Bridge and Arch bridge always use as cross roads, because they are easy to build and it cannot allow long distance between two touches.

By using iron chain, Cantilever Bridge, Cable-Stayed Bridge and Suspension Bridge Can support long distance between the touches. They are always built on wide rivers or cross the channel. Although it looks like those three kind of bridges are better than those two, these three kinds cannot use as the bridges to cross the channel. That's means those three kinds have wide limit. 

Programing

 

     When we finished building the Lego robot. It's time to let it move. It's challenging to find the correct instruction when I programed it. It shows each part as a symbol that looks similar but different from the real one. My program is based on the example that is given in the book. I let the program circulate and find out the function of each symbol.  I created the programing that allowed the robot to move forward, stop in front of the box, pull down the arm and move backward. We got the right program but it couldn't catch the box because the carpet is not smooth and it changed the way that the robot went. But after over 15times try, the robot got the box and get back.O(∩_∩)O~~

My robot

     This is the first robot we built by using a Lego EV3 programing robot. It took us a long time to put it together. It has a Programer that uses for programing every move that the robot did. Programer controls each part by using wire to send the messages and power to each electronic part that make the other nonelectronic parts move. It has an element that can manage the distance from itself to the nearest fraise which let the robot can stop at the right spot.

Introduction of Robot

     Now robots are a part of the world that we can't miss. Most of the robots are designed for the helping people to do less mechanical work to let people to free their hands and do higher level work. Some robots are for fun. They can dance, play violin, play sports etc.

     We can put robots in two types. One is industrial robots which are robots have more joints that helps for industry, the other is special robots which the robots do not work for the industry.

     Housework robots: Robots who do housework:
   

(a floor-cleaning robots )

     

     Auto-control robots: Can be re-programmed robots.

     Programing robots: Robots that need to be programed frist. Using for single way.

     

     Numerical control robots: Robots can be taught by language and numbers.

     

     Desaster robots: Help finding survivors in disaster.

Mousetrap

 

     Before I played with both ping pong ball and mouse trap. I played with the mouse trap. I got everything set (put the hold-down bar on the small button.) when I tried to put it on the floor it suddenly starts working and clipped on my finger. it's hurt for a long time but I felt how much power this small trap has.

     The extruding of the spring gives the potential energy to the equipment. Potential energy is the energy that has been stored but not be used. It converts to the kinetic energy when the  equipment is working. Kinetic energy is the energy of motion.

     The way to let the ping Pong ball go further, is get the lever arm which is hammer longer and let the ball get out of the equipment in 45 angles.

      This is a good experiment about newton's first law.