1. All objects in motion, and at rest, will stay in motion, and at rest, respectively, when no force acts on it. All objects in motion, and at rest will no longer be in motion, and move, respectively, when a force is acting upon it.
2. The effect a force has on an object is dependent on the mass, which effects the acceleration. F = ma.
3. For every action there's is an equal and opposite reaction.
Sunday 28 February 2010
Wednesday 17 February 2010
What is a machine?
Work is force x distance, and a machine is a mechanical device that makes work easier. Using a machine you can produce work, at higher amounts and faster speeds. Machines relate to work because, they produce it, and force because they exert it on objects when creating work.
Monday 15 February 2010
Questions from pages 80 (1-5), 81 (1-4), 82 (1-5)
Page 80,
1.
a. Work is using a force to move an object, work = force x distance.
b. A machine is a mechanical device that handles work. A machine is something that makes easier to do.
2. The answers A (pushing a mower), B ( Cleaning your teeth) and C (Cycling) are all work as, you are moving a mower, moving your tooth brush, and peddling your bike respectively.
3. To keep on working, you need energy from chemicals like glucose, to keep on producing force.
4. Spanners, pliers, and can openers, are considered machines, because they make work easier.
5. Tweezers, Cart, and slingshot.
Page 81
1. Pulley wheels and a rope.
2. A pulley system can help a mechanic out, by lifting the car engine up and carrying it across to a car or other area.
3.
a. A chain is used to transfer the force of the peddles and crank shaft to the wheels.
b. The Gears are needed to turn the wheel using the force transmitted by the chains.
4.Cycling in high gear is when a turn of the crank shaft makes many turns of the wheel, while low gear is about a ratio of 1 crankshaft turn: 1 or 2 wheel turns.
Page 82
1.
a.Wedges
b.Rollers
c. Ramps
2.
a.By placing them on a flat surface.
b. The crane
4. Wedges are used for putting feet into tight shoes, and ramps are used to move wheelchair people to move up higher.
5. 140m x 25,000 N = 350,000 J
NUMBER 3
1.
a. Work is using a force to move an object, work = force x distance.
b. A machine is a mechanical device that handles work. A machine is something that makes easier to do.
2. The answers A (pushing a mower), B ( Cleaning your teeth) and C (Cycling) are all work as, you are moving a mower, moving your tooth brush, and peddling your bike respectively.
3. To keep on working, you need energy from chemicals like glucose, to keep on producing force.
4. Spanners, pliers, and can openers, are considered machines, because they make work easier.
5. Tweezers, Cart, and slingshot.
Page 81
1. Pulley wheels and a rope.
2. A pulley system can help a mechanic out, by lifting the car engine up and carrying it across to a car or other area.
3.
a. A chain is used to transfer the force of the peddles and crank shaft to the wheels.
b. The Gears are needed to turn the wheel using the force transmitted by the chains.
4.Cycling in high gear is when a turn of the crank shaft makes many turns of the wheel, while low gear is about a ratio of 1 crankshaft turn: 1 or 2 wheel turns.
Page 82
1.
a.Wedges
b.Rollers
c. Ramps
2.
a.By placing them on a flat surface.
b. The crane
4. Wedges are used for putting feet into tight shoes, and ramps are used to move wheelchair people to move up higher.
5. 140m x 25,000 N = 350,000 J
NUMBER 3
Erin Brockovich - what I learned
In my opinion, the movie Erin Brockovich was bad, and predictable, but the story it is based on is mind blowing. Having seen the side of victims in the movie, researching and representing the opposition (PG&E company) was going to be interesting and a definite eye opener. What I saw in the movie was a bit biased, but I learned loads from what I was shown. We often take our environment, and planet in general for granted, for the furthering of our leisure and elimination of problems we care about. Sometimes this is taken too far, and immediate consequences take place, even for us. In the movie,PG & E dumped dangerous chromium 6 into ponds to save money, which leaked into public water supplies, and the people of Hinkley, CA, have suffered because of that. On the other hand when representing PG & E as lawyers, in defense of a lawsuit caused by the water contamination. I learned the real affects of Cr6 and how the Erin might have changed some of the facts and way she said them. I researched the laws concerning the court hearing, and thought of how Erin could have used the plight of the residents to convince the jury and the judge on only biased ethical and moral grounds, not on full use of evidence. I would conclude that both sides of the conflict and valid points, and showed how people can use science and slight deception to convince people one way or the other. But more importantly how mankind must think for the environment and other people, for the present and future before doing anything that may affect those.
Sunday 14 February 2010
Forces (number 3 on wiki)
A force is a physical influence that is caused by the laws of physics. Here are for common forces; gravity, gravity is the gravitational pull of the Earth that pulls all things to the center, or close to as it, like the ground above the surface. The more weight that something the stronger the gravitational pull that the Earth has on the things. Air resistance,when a object goes through the air, it has friction with the air, and this forces the object to move slower if it is moving, as it makes going through harder. Mechanical force, is force made by a machine that makes work (force x distance). Drag, the force that is made when a object rips through the air, and air resistance slows a object going down and makes the process of going down look like the object slightly being dragged back up a little. Forces are measure in newtons. Force = mass x acceleration.
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