Young Minds For Math & Science: March 2012

Friday, March 30, 2012

My science project "The Pulley Station"

Hey guys the photo above is my science project.
how it works: as you pull the rope and put an object on the hook it will lift the weight up!

Notice: everything is made of wood. ** Even the pulley !!

I made it like this (out of wood) because back in the old days there were only wood pulleys because iron didn't come out.

BY: Alisha Bagga
Class: 8BH

Tuesday, March 27, 2012

Dance Presentation - Global Warming

Here is our Dance Prezi on Global Warming. Click the link below.

http://prezi.com/dxycaqplydwv/global-warming/

Monday, March 26, 2012

how to know when to multiply or divide in word problems

http://www.ehow.com/video_12218960_divide-multiply-fraction-word-problems.html

Wednesday, March 21, 2012

Are you all confused about HOW TO MULTIPLY/DIVIDE fraction?

Take a look at this video it might help you guys out!!! :)

http://www.youtube.com/watch?v=B7MtFQW7i_I

Good luck on your math test on Monday!!

HOW BIG IS THE UNIVERSE?

How big is actually our universe? Can we really comprehend it?
Here is a wonderful piece put together by some smart people to give us a hint about how BIG our universe is.
Just click the link below and wait for it to load.
Enjoy it!

How Big is The Universe?

Tuesday, March 20, 2012

Mechanical Advantage

I found some information on mechanical advantage

http://www.wisc-online.com/Objects/ViewObject.aspx?ID=ENG20504

Sunday, March 18, 2012

Calculating the IMA of a Simple Machine

1. A ramp that is 5 m long is used to raise an object 2 m vertically. Find the IMA of this ramp.

2. The handle of a screwdriver has a radius of 3 cm. If the shaft of the screwdriver has a radius of 0.5 cm, what is the IMA of the screwdriver when used to tighten a screw?

3. Wei uses a pulley system to lift a box. She pulls the rope a distance of 3 m, suing a force of 50N. If the work done on the box is 120J, what is the efficiency of the pulley system?

4. Define “simple machine”

5. Explain how a lubricant affects the efficiency and the frictional forces of a machine

6. Explain why a machine or a mechanism cannot have an efficiency of 100%

7. A force of 900 N pushes a wedge 0.10 m into a log. If the work done on the log is 50 J, what is the efficiency of the wedge?

8. A machine is capable of doing 35 J of work when 50 J of work is put into the machine. What is the efficiency of this machine?

9. List the six simple machines that you know.

10. What is the difference between IMA and MA?

Thursday, March 8, 2012

One of the worlds biggest machines

Monday, March 5, 2012

1st Class & 2nd Class Levers

Hey guys! So this video gives you a better idea of 1st class levers and 2nd class levers if you're a bit consfused. It also has a cool theory about coke cans :D

^ Just Copy and Paste. :)

Machines

Hey guys! I'll be having a science test pretty soon, so I read over the textbook, made notes. If your able to understand all my notes, then you're pretty well prepared. But please do anticipate questions on the test for like short answer and do it now so you can just recite it during the test.

Notes:
Systems + Questions
Machines + Questions

Sunday, March 4, 2012

Rubric For the Science Project

RUBRIC: SCIENCE AND TECHNOLOGY, (MECHANICAL SYSTEMS).

(8 OA& BH)

Categories	Level 1	Level 2	Level 3	Level 4
Knowledge of content e. g. facts; terminology; definitions; safe use of tools,)	demonstrates limited knowledge of content	demonstrates some knowledge of content	demonstrates considerable knowledge of content	demonstrates thorough knowledge of content
Understanding of content (e.g., concepts, ideas, theories, principles, procedures, processes)	demonstrates limited understanding of content	demonstrates some understanding of content	demonstrates considerable understanding of content	demonstrates thorough understanding of content
Thinking and Investigation (e.g., formulating questions, identifying the problem, developing hypotheses,)	uses critical/ creative thinking processes, skills, and strategies with limited effectiveness	uses critical/ creative thinking processes, skills, and strategies with some effectiveness	uses critical/ creative thinking processes, skills, and strategies with considerable effectiveness	uses critical/ creative thinking processes, skills, and strategies with a high degree of effectiveness
Communication (e.g., clear expression, logical organization) in oral,visual, and/or written forms (e.g., diagrams,models)	expresses and organizes ideas and information with limited effectiveness	expresses and organizes ideas and information with some effectiveness	expresses and organizes ideas and information with considerable effectiveness	expresses and organizes ideas and information with a high degree of effectiveness

Review Questions on Mechanical Systems

Review Questions on Mechanical Systems

Part 1: Definitions

A. Wedge _____ A rigid bar with the fulcrum between the input and output forces.

B. Inclined Plane _____ A grooved wheel with a rope or cord.

C. Screw _____ A sloping surface on which an object can move.

D. Wheel and Axel ______ A rigid bar with the input force between the output force and fulcrum.

E. Fulcrum ______ An inclined plane that travels through an object.

F. Pulley ______ The point on which a lever is supported.

G. 1^st Class Lever ______ An inclined plane wrapped around a rod.

H. 3^rd Class Lever ______ A shaft that is attached to a larger disk.

Part 2: What type of machine?

1. A screwdriver ______________________________________

2. Stairs ______________________________________

3. A doorknob _____________________________________

4 A sword _______________________________________

5. A shovel ________________________________________

6. The inside of a jar lid _____________________________________

Part 3: Types of levers (give the order of Input, Output, and Fulcrum for each lever)

1. First class lever: Input_____ Output_____ Fulcrum _____

2. Second class lever: Input_____ Output_____ Fulcrum _____

3. Third class lever: Input_____ Output_____ Fulcrum _____

Part 4: Calculating Mechanical Advantage

1. A moveable pulley system with three pulleys and 4 support ropes ________________

2. A second class lever, the input force is 1 m from the fulcrum, the output force is

5 cm from the fulcrum ___________

3. The inclined plan is 5 m long, and 50 cm high ____________________________

Part 5: 10 Questions About the Previous Chapters

1. What is work? ____________________________________________________________________________

________________________________________________________________________________________________

2. How do you calculate work? _____________________________________________________________

__________________________________________________________________________________________

3. What type of force is friction? _______________________________________

4. How many joules are required to move a box 5 m with a force of 45 N? _____________

5. How much force should be inputted into pulley with a mechanical advantage of 1 if you need to lift a weight that is 12 N? __________________________________

6. Sugar is an example of what type of energy?__________________________________

7. If you apply 20 N of force to a machine with a mechanical advantage of 0.5, how much force would the machine put out? ______________

8. What do you call a device made of 2 or more simple machines? ______________________

9. What increases when you have a mechanical advantage of less than 1?

___________________________________________________

10. How much force is required to lift a 24 kg weight? ___________________________________

11. When is work done?

12. Mr. A. lifts a rock 1.5 m by applying a force of 20 N. How much work does Mr. A do on the rock?

13. You did 450 J on an object and you pushed object 15 m at a constant speed. How much work did you do on the object?

14. What is the difference between Mechanical Advantage and Ideal Mechanical Advantage?

15. Explain three ways in which machines help us to do work.

16. Calculate the mechanical advantage of a machine that exerts a force of 160 N on an object when you exert a a force of only 20 N.

17. Use the concept of energy to explain why ideal mechanical advantage is not the same as mechanical advantage for real machines.

18. What concept is represented by the ratio of the output force to the input force?

19. Write the mathematical equation to calculate the IMA of Wheel and Axle.

20. The handle of your garden tap has a radius of 4.0 cm, and is connected to a shaft with a radius of 0.80 cm. What is the ideal mechanical advantage of this wheel and axle?

Happy Reviewing!

Science Project # 1 (Mechanical Systems)

Science & Technology: Mechanical Systems.

Project # 1

What Students will do?

(“Engineering is the application of science to develop solutions and design structures that are useful to the people. For example, you might need to lift a large mass to the top of a sky scraper.”). (Lionel Sander et al, 2008). You have just been appointed as the new City Engineer, your job as the city Engineer will be to see how you can apply your engineering skills to solve problems that are facing the city.

Design and construct a device made from simple machines that you can use to perform simple tasks. Your design is any simple machine that you dream about; you are at liberty (freedom) to design any type of machine you like. Think about all the simple machines we have learned about in the unit on “Mechanical Systems that we just concluded. In your design think about the concepts of Mechanical Efficiency, Mechanical Advantage, Ideal Mechanical Advantage, Work, Energy and Force.

Criteria for Success

1. Your final design must include at least one simple machine.

2. Input force may be applied by your hand.

3. Your mechanism must be able to perform simple task.

4. Your design must allow for measurement of the force applied by your hand.

5. Use your imagination to add more features.

You can do this project in peers. Ask questions if you need more clarification.

Good luck!

Mechanical Systems

Below I have posted the link to a prezi presentation that I have made for science. The presentation contains a few of the terms we have learned in Science so far, in mechanical systems.

http://prezi.com/yqoum331rpie/systems-in-action/