Thursday and Friday's Science Class

Hey Everyone!

On Thursday's class we began by Ms. D checking over our Homework which was Acceleration Practice 2. It consisted of 8 math problems where we had to find either acceleration, velocity, or the time. Here is the link to Moodle for Acceleration Practice 2 for anybody who was absent:

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

The answers for Acceleration Practice 2 are as follows:

1. A= 0.02 m/s/s

2. A= -67 m/min/min

3. A= 1.56 cm/s/s

4. A= -38,733.33 km/h/h

5. A= 156,250 km/h/h

6. T= 1.43 s

7. Vf= -2.21 km/min

8. s=7.57 m/s, T= 2.05 s

After checking the homework, we began working on our Acceleration lab with the three different balls. We could choose to either put all three ball's data on one graph, or three individual graphs. Remember if you're doing only one graph to make three different colors for the balls. This is what an acceleration graph would look like:

This graph is showing acceleration of an object free-falling. For more information on acceleration, check out this website with additional information on acceleration and other types of motion we've been working on. http://www.historyforkids.org/scienceforkids/physics/movement/acceleration.htm

Our only homework for Thursday was to study for the quiz we had last science class (Friday). Here is a link to a video on almost everything that we covered in motion. http://www.kidsknowit.com/interactive-educational-movies/free-online-movies.php?movie=Acceleration

Friday's Class

During Friday's science class we didn't do too much because we were taking the quiz on everything we learned on motion. The quiz grades should be on Powerschool for you to check your grade. After finishing the quiz our only task was to work on the graph(s) for the Acceleration lab with the ping pong ball, soccer ball, and the tennis ball.

Homework

1. Finish plotting all the data on your graph(s). Don't connect the dots because we will be doing that during Tuesday's class.

2. Our fourth blog comment is due on Friday, December 10, by 16:00. Remember that we have to have 3 comments on the eighth grade blog and 4 on our seventh grade blog minimum.

We watched some videos in class on Thursday. The songs are by "They Might Be Giants". The first one is more about motion and the second video is kind of relative, its about the elements.

1. http://www.youtube.com/watch?v=DRb5PSxJerM

2. http://www.youtube.com/watch?v=d0zION8xjbM&feature=related

The next scriber is....... DAVIDE!

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)