Measuring work

We continued with yesterday's topic of work by using the motor/pulley system. We found the work done by the motor, washers and a sled.

Homework:
1. Complete reflection questions A-E on pg 78


2.Answer on your original HW paper (hardest work). Would the science community view what you did as work? Explain.
 
Quiz tomorrow! (Circuits and work)

What is work?

In class we discussed how a scientist would classify work being done. Know that you need 2 things: force and distance. If one of these elements is missing then there is no work being down. You should have learned that laying on the couch does not count as you doing work!

Complete the practice problems for homework (they are on the back of the circuit paper). Lost the paper? See link under Class Info. Remember that the equation is Work = Force * Distance

Reviewing electricial circuits

We used the following website to help us review the 2 types of circuits made on Friday. Practice making your own circuits and review for your quiz on Friday! 

http://phet.colorado.edu/en/simulation/circuit-construction-kit-dc-virtual-lab

Homework: Complete worksheet on electrical circuits (do not do the side on work, that's tomorrow!)

Investigating electrical circuits

We did some experimenting today by creating two types of electrical circuits: series and parallel. We will review each type and discuss on Monday.

Looks like a beautiful weekend. Enjoy it! And Go PHILLIES!!!!

Investigating motors

Today's class investigation led us to discover how the following affect the performance of a motor:

• number of batteries used
• the way the batteries are connected (series vs. parallel)
• winding the string around the pulley vs. the nail

Although some groups may have had some difficulties with the equipment you should have found that batteries in a series worked more effectively than in a parallel. Also the string around the nail worked the best. Use this to complete the #1 A-D on pg 67 for homework.

Variables that affect friction

Today we shared our findings from Lesson 6 and took notes on what variables affect the force of friction.

There will be a quiz Tuesday, October 19, 2010. Topics include forces (elastic, gravitational, friction) and calculating net force. We will review on Monday.

Investigating friction

The class was divided up to investigate if frictional force is affected by: surface type, weight, or surface area.

Tomorrow and Thursday you will work on your lab report. Laptops are available in class to type up your good copy. All lab reports are due by Friday.