Calculating net force

We reviewed the gravity studyguide/worksheet that was completed in class on Thursday. We also learned how to calculate the net force acting on a given object. Practice problems were given in class. If you did not finish time will be given at the beginning of Monday's class. No need to complete over the weekend. Enjoy the weather...it's going to be a great weekend :)

BTW--> Go Phillies!!

Forces review

We took notes on forces and how gravity affects objects. In class, we also completed a studyguide on gravity.

Reminder that the homework for the week is due tomorrow.

Investigating elastic force

This week our investigations will lead us to thinking about forces. Today, we looked at the force needed to stretch a rubber band. There are 2 questions we want to answer:

1. What happens to the force required to stretch a rubberband when the stretching distance is doubled?
2. Based on the graph, is there a relationship between the force needed to stretch the rubberband and the distance it stretches?

Please have your data graphed for tomorrow's discussion.

Also, HW for the week has been assigned today. See Class Info for a link to the assignments. Keep in mind that work not finished in class may be assigned as additional homework.

QUIZ WEDNESDAY! Study parts of a battery, energy forms and transformations.

What is work?

What we consider work and scientists consider work are 2 different things. In class I reviewed how to calculate work if given force and distance. Please review the problems you worked on in class on Wednesday and complete Student Sheet 8.1b. Do not complete 8.2. That is for Friday's lab.

***The quiz scheduled for Friday has been rescheduled for Monday***

Circuit review

It seems like ages ago we were here (thank you Mother Nature!). We reviewed different types of electrical circuits: series vs. parallel. To practice making your own circuits check out the link below.

http://phet.colorado.edu/simulations/sims.php?sim=Circuit_Construction_Kit_DC_Only

HW Tonight!: Write a paragraph describing the hardest work you have ever done. Explain what you did, what forces were being used, and what could you have done to make the work easier on you.

There will be a quiz on Friday on circuits and work. (We have not covered work yet-- that is Wed. and Thurs. lessons).

Finding the best operating conditions

That was the goal today. What setup will lift the most number of washers? Tomorrow we will share our obseravtions and determine the maximum force the motor can lift.

QUIZ UPDATE: Due to the impending snow storm Wednesday, the quiz will now be a take home quiz. Quizzes will be issued tomorrow and will be DUE THE DAY WE RETURN TO SCHOOL. If you do not return the quiz on the day we return, you will be issued a time either afterschool or during lunch next week to take the quiz (again). I am not accepting quizzes past the date we return (if you are absent then yes I will accept).

Sliding friction

The three investigations done in class this week has led us to discover that:

• The force of sliding friction depends on the type surface it is moving across.
• The force of sliding friction increases as the weight increases.
• The force of sliding friction does not depend on the surface area of the block in contact with the surface.

You used a spring scale to measure the force that counterbalanced the frictional force. This was evident when you pulled on the scale at a steady rate. Your effort force is equal to and opposite the frictional force. (Newton's Third Law!)

We also discussed another type of friction- air resistance. Keep in mind the variables you tested in class would affect objects differently in the air. (Surface area matters when you are flying through the air!)

Reminder: HW list and lab reports are due tomorrow!

Collecting Data on Friction

We used the class period today to collect data on the assigned variable and friction. You now have all the info needed to complete your lab report. All lab reports are due by Friday. Any lab report received next week will lose points each day.

Investigating friction

Our investigation on forces led us today to think about how the effort force will change due to surface type, weight of the load, and surface area. Groups were assigned one set of variables to test. In class you began writing your lab report for this lesson. Tomorrow, you will conduct the lab and finish the lab report.

All lab reports will be given a test grade and are due no later than FRIDAY, FEBRUARY 5!

Also due Friday ~ HW list for this week.

Net force

Concepts covered today:

• Reviewed properties of gravity
• Calculated net force on an object

HW lists have been given out for the week. Reminder that all 4 assignments are due by Friday, February 5.
Lost your homework list? Check out the link in the upper right hand corner!

Mass vs. Weight

Today's investigation led us to examine what effect mass has on an object's weight. Tomorrow we will discuss your findings and look at gravitional force on Earth and other bodies in the solar system. This still leaves us with the question: DOES MASS CHANGE IN SPACE?

We have completed Inquiry 5.1 and 5.2. You are now able to complete ALL  HW assignments for the week.

Reminder: Notebook Quiz on Thursday (Energy and batteries)

Intro to Forces

In class we used a rubberband to get us thinking about common forces. Our investigation led us to find that the distance that a rubberband is stretched is proportionate to the force needed to stretch. Tomorrow, we will look for a relationship between weight and mass.

Reminders:

• Notebook Quiz Thursday ~ Energy and Batteries
• MOS logs due Thursday
• All missing/make up work is due Thursday

Homework: Doing something a little different this marking period. All HW for this week only was assigned today. All HW is due no later than Friday. There is a section with links at the top of this page.