Today we didn't do much of anything that is new.
What we did was work more on the lab worksheet we were given on December 12, aka Friday. I believe that is due tomorrow, but that is just an assumption.
We were also given the answers for "Concept-Development Practice Page 13-1 -- Chapter 13: Gravitational Interactions", so here they are:
1. An apple that has a mass of 0.1kg has the same mass wherever it is. The amount of matter that makes up the apple
DOES NOT DEPEND UPON
the location of the apple. It has the same resistance to acceleration wherever it is -- its inertia everywhere is
THE SAME.
The weight of the apple is a different story. It may weigh exactly 1N in San Fransisco and slightly less in mile high Denver, Colorado. On the surface of the moon the apple would weigh 1/6N, and far out in outer space it may have almost no weight at all. The quantity that doesn't change with location is
MASS,
and the quantity that may change with location is its
WEIGHT.
That's because
WEIGHT
is the fore due to gravity on a body, and this force caries with distance. So weight is the force of gravity between two bodies, usually some small object in contact with the earth. When we refer to the
WEIGHT
of an object we are usually speaking of the gravitational force that attracts it to the earth.
2. If we stand on a weighing scale and find that we are pulled toward the earth with a force of 500N, the we weight 500N. Strictly speaking, we weight 500N relative tot he earth. How much does the earth weight? If we tip the scale upside down and repeat the weighing process, we can say that we and the earth are still pulled together with a force of 500N, and therefore, relative to us, the whole 6 000 000 000 000 000 000 000 000-kg earth weighs 500N! Weight, unlike mass, is a relative quantity.
Hmm, that seems to be it.
OH, also, if you are bored read pages 5 and 6 for tomorrows class in the Dynamics booklet. And tomorrow we have another lab, so don't miss it!
The scribe for tomorrow shall be... Anthony L!
Toodles!
Showing posts with label dynamics. Show all posts
Showing posts with label dynamics. Show all posts
Monday, December 15, 2008
Friday, December 12, 2008
Good Morning bloggers
well its a new beautiful day today! well in class yesterday, thursday the 11th, (sorry about my spelling and what not) we had our dynamics test!! woot! it was pretty simple test and i don't know what else to say. O ya! Ms.K gave us that new booklet of notes that we should read before today's class. I think that's all we did? test and the new book for the new unit? ya?alrity then cya all in class!! next scribe is rebecca.
Wednesday, December 10, 2008
Class on Wednesday, December 10, 2008
I'll revive this fairly deceased blog by re-initiating scribing. *cough* bonus marks *cough* I mean there is a test tomorrow on the unit, dynamics - a branch of mechanics that deals with forces and their relations to patterns of motion. I posted the sheet consisting of anagrams because it was from the past and no one was blogging for quite a while. Okay, so euphemistically, there is a lovely and highly admired test tomorrow. Good luck to everyone. There is an immaculate review below as posted by our teacher to remedy any difficulties that one may stumble upon while writing the test. Below are sheets I scanned, so feel free to browse.
remember that there is no air resistance when a rock is in free fall. that was my first instinct but then i asked for the opinions of others
for 8b) Ms. K said the answer being force RESISTING the car's motion was 3740N, but I still object. The force of the car caused by acceleration is 3740N as calculated by multiplying the mass and acceleration. To further justify, it states that the force put on the wheels due to the road is 5600N, which is a frictional force and what we are trying to find is the resisting force being the force impeding the car. So I obtain the difference between the two resultant forces which results in 1860 N [East]. Friction resists, so this is the resisting force.
We went through the sheets above and received back our assignment on vectors. Well this is a fairly accurate summation of class today. I dub the next scribe Sir Dion Palumbo. He's a lucky duck to be the scribe for the day of the test. Thou shall scribe effortlessly because of the sympathetic initiator.
Thursday, December 4, 2008
Force And Acceleration Lab
Hi there!
Sorry I forgot to blog yesterday.
Anyway, here's the lab that we did yesterday and today:
First of all we should know the Newton's laws;
First Law - When no net external force is acting on an object, it will either remain at rest or if it is moving, it will continue to move in a straight line at a constant speed.
Second Law - If an unbalanced force acts on an object, the object will undergo an acceleration directly proportional to the magnitude of the force.
Equipment:
Recording Timer
Washers
Lab Cart
Paper clips
Carbon Paper Discs
Pulley
Long Flat board/surface
Timer Tape
String
50 g
100 g
200 g
Procedure:
1. Load the cart with the weights (50, 100 and 200 grams). Attaach one end of the string to the cart. Tie a paper clip to the other end of the string and pass it over the pulley. Hang the metal washers on the clip until the friction force acting on the cart is just offset. Forces due to friction are offset when you can give the cart a very slight push and it moves at a constant speed across the table. Do no removethe added weight at any time.
2. Pull the end of the timer tape through the timer and attach it to and end part of the cart. For the first trial, reemov the 50 g mass from the cart and hang it on the end of the string.
3. Star the timer and release the cart. Stop the timer and the cart when the cart reaches the pulley. Renove the timer tape and label it "50 g trial" on the end that was attached to the cart.
4. Remove the 50 g mass from the string and put it back on the cart. Remove the 100 g mass from the cart and place it on the end of the string. Make and label a second tape in the same way as you made the first tape.
5. Repeat steps 2 and 3 for 150 g, 200 g, and 250 g.(as a result increasing the mass by 50 g each time.) Be sure to place each mass on the cart after using it.
6. In this investigation, wour cart will in general undergo less acceleration than did those of prior investigations. For this reason, it is best to use a larger time interval than thoose used in earlier investigations. Label the first dot on each tape zero. Label every ffith dot after that 1, 2, 3, 4 and so on. The distance between two each numbered dots represents one time interval (a "tock"). The distance between each numbered dot is numerically the same as the avaerage velocity for each time interval. The distance is also numerically the same as the instantaneous velocity for the midpoint of the time interval. Measure each distance on each tape carefully and record al your values.
Interpretation:
1. On the same graph, make a velocity versus time plot for each tape. Plot veloccity on the vertical axis anad the time interval on the horizontal axis.
2. The slope of a velocity time graph is (Vf - Vi)/t, which is the acceleration. Determine the slope of each of the lines on your velocity-time(tock) graph. Record each value.
3. Plot a graph of acceleration versus force with force on the horizontal axis.
4. Explain the meaning of the graph. Does it substantiate Newton's second law?
The next blogger is Thoa:-)
Sorry I forgot to blog yesterday.
Anyway, here's the lab that we did yesterday and today:
First of all we should know the Newton's laws;
First Law - When no net external force is acting on an object, it will either remain at rest or if it is moving, it will continue to move in a straight line at a constant speed.
Second Law - If an unbalanced force acts on an object, the object will undergo an acceleration directly proportional to the magnitude of the force.
Equipment:
Recording Timer
Washers
Lab Cart
Paper clips
Carbon Paper Discs
Pulley
Long Flat board/surface
Timer Tape
String
50 g
100 g
200 g
Procedure:
1. Load the cart with the weights (50, 100 and 200 grams). Attaach one end of the string to the cart. Tie a paper clip to the other end of the string and pass it over the pulley. Hang the metal washers on the clip until the friction force acting on the cart is just offset. Forces due to friction are offset when you can give the cart a very slight push and it moves at a constant speed across the table. Do no removethe added weight at any time.
2. Pull the end of the timer tape through the timer and attach it to and end part of the cart. For the first trial, reemov the 50 g mass from the cart and hang it on the end of the string.
3. Star the timer and release the cart. Stop the timer and the cart when the cart reaches the pulley. Renove the timer tape and label it "50 g trial" on the end that was attached to the cart.
4. Remove the 50 g mass from the string and put it back on the cart. Remove the 100 g mass from the cart and place it on the end of the string. Make and label a second tape in the same way as you made the first tape.
5. Repeat steps 2 and 3 for 150 g, 200 g, and 250 g.(as a result increasing the mass by 50 g each time.) Be sure to place each mass on the cart after using it.
6. In this investigation, wour cart will in general undergo less acceleration than did those of prior investigations. For this reason, it is best to use a larger time interval than thoose used in earlier investigations. Label the first dot on each tape zero. Label every ffith dot after that 1, 2, 3, 4 and so on. The distance between two each numbered dots represents one time interval (a "tock"). The distance between each numbered dot is numerically the same as the avaerage velocity for each time interval. The distance is also numerically the same as the instantaneous velocity for the midpoint of the time interval. Measure each distance on each tape carefully and record al your values.
Interpretation:
1. On the same graph, make a velocity versus time plot for each tape. Plot veloccity on the vertical axis anad the time interval on the horizontal axis.
2. The slope of a velocity time graph is (Vf - Vi)/t, which is the acceleration. Determine the slope of each of the lines on your velocity-time(tock) graph. Record each value.
3. Plot a graph of acceleration versus force with force on the horizontal axis.
4. Explain the meaning of the graph. Does it substantiate Newton's second law?
The next blogger is Thoa:-)
Tuesday, December 2, 2008
Video mr.same same
Hi! Everyone...it's me Larlyn014 your scribe for today's class...
Today!
We watch a video of mr. same same..I think that's what they call him....anyways...it's about Inertia force.
INERTIA FORCE
Today!
We watch a video of mr. same same..I think that's what they call him....anyways...it's about Inertia force.
INERTIA FORCE
- Inertia in other words mass
- Mass in other words Matter
Note: If you have an arrow with a bow then shot it. What's keeping the arrow moving? There's no any things that keeping it moving Inertia that make who make it move by itself.
Sorry that's the only I remember on what we just watch. And I remember there's another example he shows to prove things more clearly.
After watching that Mrs. Kozoris let us finished the worksheet she gave from yesterdays class.That's all for today.
Im really sorry I didn't explain things more clearly. I was trying to find video to clear things up and this is what I found
Here's another one.....example of Newton's First Law
THE INERTIA
Next scribe Intrepid ^_^
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