Acceleration and Deceleration Testing

The first thing we did when class started on Tuesday is we received our graded, bean bag lab rubric. Then we did two math practice problems on page 25 of our textbook, because a couple kids had problems on a few of their calculations for the lab. After that, we went through our "Acceleration Calculations" math practice sheet that we had to do for homework. Most of us had errors with one or two of the questions and they are now homework for Tuesday to complete. Finally, the last thing that we did for the rest of the class period was a class lab, called Acceleration/Deceleration Testing.

The purpose to the lab was:
What does a graph look like when an object is accelerating?

Under that we had to have the IV and DV, which were:
DV: Graph
IV: Object accelerating

Then we went outside to practice with the timers, and then test. Our data was recorded down on three different tables: one for the ping pong ball, one for the tennis ball, and one for the soccer ball. Everyone in the class had a different position at one, two, three, etc. meters, all the way to 12 or 13. I was at one meter (that's why I'm not sure how many positions there were), which was really hard because I had to have little mistakes and be almost exactly on the right times of when the ball started and then reached my point. For each ball, we did three tests just in case of a mistake with the timer, which was surely going to happen. Then under the three trial spots, we had to calculate the average, but we did that when we were done testing and back in class.

Then under the data tables, we answered the purpose question individually, and then discussed it as a class. We concluded that the graph would have a positive correlation because as the time increases, the objects speed also increases.

Then we did a sample calculation, and here is an example of one.
S=d/t
S=1m/1.2s
S=0.83 repeated

And at the end, we had to glue in the small, bottom of the lab page, homework sheet, that we're probably going to talk about next class after we finish the class wide table. It's not homework yet, so don't worry about it now.

That is what we did during Tuesdays class, and the next scribe is Jakub!

Here is a link to moodle: http://zagreb.ceesa.net/

Fridays class

On Fridays short class we worked on acceleration, and as you can see, many other things. We took notes in class, such as these, and Ms.D wrote a lot of formulas and explanations on the board about acceleration. This is all we did the whole class, except for a worksheet we got at the end of the class, which has eight questions on it.

Homework Questions:

• A three toed sloth is moving at the speed of 2m/min. It takes 30min to increase its speed to 15m/min. What is the sloth's rate of acceleration?
• A bicyclist is travelling at a speed of 416m/min when he approaches a hill. It takes him 2 min to travel down the hill. At the bottom of the hill, his speed has increased to 620m/min. What was his acceleration?
• A ball is rolling up a small incline. At the bottom of the hill it is moving at a speed of 5cm/s. Calculate the deceleration of the ball.
• A motorcycle is travelling at a speed of 45km.h. It takes 5s (0.0014 hours) to increase its speed to 65km/h. What is its acceleration?
• A car company claims that the car can go from 0km/h to 60km/h in 7s. What would the acceleration of this car be? ( Seconds should be to the closest 10,000ths when you convert them!)
• A bean bag is dropped out a window. When it falls, it accelerates at a rate of 9.8m/s². If the bean bag hits the ground after 10 seconds, what is its velocity just before it hits the ground? (HINT: What is the initial velocity before the bean bag starts to fall?)
• The same bean bag is dropped out of the same window again. How long does it take for the bean bag to reach the speed of 50m/s? (Everything is the same as above except time!)
• A train travels at a speed of 390km/h can decelerate at the rate of 4500km/h/h (4500 km/h²). How long will it take the train to come to a complete stop?

Relative motion:
-dependent upon an object’s reference point
Velocity= speed + given direction
example= 40 kmph heading north
*GPS*, pilots, air traffic controllers

Graphing Motion:
use a line graph-> shows change over time
Time - on x-axis (possibly)
Distance - on y-axis (possibly)
Speed - on y-axis (possibly)

Slope -> steepness of a line

Acceleration:
Speed increase (positive); Speed decrease (negative); Direction changes (positive or negative)
Speed increase= object starting motion from a stopped point; Speed decrease = object is in motion and is coming to a stop

Circular motion:

• Continually changing its direction
• Continually changes its velocity
• Continually changes it acceleration

To calculate acceleration:
Acceleration=
(Final velocity-Starting velocity)÷Time

http://www.wfu.edu/physics/demolabs/demos/avimov/mechanics/loop_de_loop/loop.rm

The next post is...Nathan!

Friday science class

On Friday we started the class by finishing the "Bean Bag Drop" lab, some people are almost finished with it and and some not. Ms.Erfle showed us how to do the graph and she also helped us with other thing that we had to do. The way she explained how to finish the graph was like this:

1. That we have to have the date and title at top of our page (and our graph should be line graph)

2.That we should label X the time and the Y should be distance

3.Then we have to label the numbers on our X-Y

4.Then we have to graph the average on the

Thus are the way we had to finish the lab. The second thing we had to do for the graph was to answer some questions that related to the graph. If we finished every thing that was for the graph then we could move on to the next thing that it was find the speed with the average and the distance. We only had to show the formula-plug-chug once at the top of our page. After we finished finding the speed problems then we could move on to the last thing that we had to do for the lab was to finish conclusions. In conclusion there is 5 questions in that we have to answer. After that you could organize your lab not book.

(The lab should be finish on Thursday)

Global Warming & Climate Change PSAs

Tuesday, November 16th, 2010


If you are interested in viewing the PSAs (Public Service Announcements/Commercials) created by the 7th & 8th Graders during the first quarter, please check out YouAISZ on YouTube. This is AISZ's YouTube Channel.

YouAISZ on YouTube 

Feel free to leave comments or let us know if you enjoyed the creations!

Thursdays Class

Today during our normal science block we started a new project, which was a lab, called "How Long Does It Take a Bean Bag to Drop?" The purpose of this lab was to see how the distance an object is dropped affects the time it takes the object to fall.

We dropped bean bags from different heights:

• the seat of a chair in the science lab

• the lab table

• top of the doorway

• two different heights of stairs.

We dropped the bag three times from each height. That was the fun part!
After we had finished dropping the bags and finding out the time, we had to graph the data we got and the find the average speed. To find the speed you divide the distance by the time. By this time class had already ended, so we finished the rest in the next class. I think that everyone agrees that this was one of the more interesting labs we have done so far. This class was a long class, but there isn't much to say because we only worked on our lab.



Useful definitions for distance, average speed and speed:

Distance: The extent of space between two objects or places.

Average Speed: The overall rate of speed at which an object moves; calculated by dividing the total distance an object travels by the total time.

Speed: The distance an object travels per unit of time.



Cheek out Moodle: http://zagreb.ceesa.net/course/view.php?id=188

Big Bean Bag Drop for Fun: http://www.youtube.com/watch?v=g0xolhvmbSk



Next Scribe is Ghazaleh!

This video is just to show how the project was done.

Co-authors Ghazaleh, Courtney, and Emilija

Speed, Time, and Distance

Today during the short science block we had time to talk about our homework. Our homework was to do all the questions of the paper Ms. D gave us (Speed Practice Problems). We talked about the answers and talked about how we need to use Formula - Plug - Chug and how we always need to write the formula and the units. If you didn't catch the answers here they are, but be sure to write the formula, the plug, and the chug:

1. An opel car travels 736 km in 8 hours. What is the speed of the car at that time? S = 92 kmph
2. If a horse travels 52 m in 3 minutes what is the rate of the horse? S = 17.33 mph
3. A plane flew for 7.95 hours between Chicago and London, if its speed was 812.7 kmph what was its speed? D = 6460.57 km
4. The speed of a lion going for a kill is 12 m/s. How much time will it take the lion to run 37 m? T = 3.08 seconds
5. If a runner can go 3.25 m/s and runs for 2.32 hours during a race, what is the distance covered during the race? D = 27,144 m
6. A balloon travels approximately at the speed of 46.9 kmph. Calculate the time in hours it takes to tracel 26,578.64 m. T = 0.57

If you lost your sheet you can find our home work sheet on moodle on this link:

http://zagreb.ceesa.net/course/view.php?id=188 and on that link you can also find our next homework assignment. Our next homework is to do the other sheet, Speed Problems #2. The first two are easy, the second two to are getting harder and the last two you need to really concentrate. And remember the triangle: For distance multiply speed x time, for speed divide distance/time, and for time divide distance/speed. And remember Formula - plug - chug!

The next scribe is Emilija!