Solar Cooker Project Physics

Description:  Build a solar powered device that cooks an egg within a 30 minute time period while positioned over grass.  

You should build and test several versions before test day to ensure a good grade.  

The device must be small enough to transport to class regularly when folded, and must have a mechanism to prevent it from blowing away or falling over unaided.    Nothing larger than 70cm L X 70cm W X 70cm H , and must be completely powered by the sun.  No fossil fuels or combustion or electricity.  You may not use solar electric panels.  

Partners:  Individual or teams of two allowed.  Different grades will be assigned to partnerships if one partner fails to demonstrate understanding and or work on the project.

Value:  100 points

Due Date:   Monday June 5, 2017  during class for per  4 , per 7   and after school 2:35 for per 1 and 3

Grading:

Fully cooked egg, firm or rubbery with no give  (yolk and white ) = A ((90-100)  (Not translucent, everything solid, no runniness)

¾ cooked egg  = B (89.5-80) (Mostly non translucent (mostly white) , Significant runniness or yolk partially cooked)

½ cooked egg = C  (70-79.5) (Significant translucence, runniness and yolk mostly uncooked)

¼ cooked egg = D (65-69.5) (Mostly translucent, yolk uncooked, very little cooking.  

No cooking = F      (50-64.5) (No evidence of cooking but you test a cooker)

No device tested = F  = Zero

Extra + 2 points if the total market value of materials is less than $10 as decided by the instructor.  Reusable cook pots are not part of the calculation, but glass, plastic, foam, paint do count.   Try and use as much post consumer material as possible if appropriate.    Example---- substituting  shredded newspaper as insulation instead of builders fiberglass or foam.

A ten point deduction will be assigned  to projects that do not have  active defense against wind or tipping over.  Plan on their being wind on test day.   3-4  tent stakes with strings firmly attached to your cooker is sufficient.   o

Oceanography Acids and bases Worksheet Questions

Exploring Acids and Bases

In class, you learned that pH is inversely related to the concentration of H⁺ ions by the following equation: pH = -log[H⁺].  Lower pH values have higher [H⁺] while high pH values have lower [H⁺].  Acids have a lot of H⁺ ions and donate them to other molecules.  Bases accept H⁺ ions.  We will explore this relationship further using an online simulation of acid-base solutions.

1. Please go to the following website: http://goo.gl/V0YcK

2. This should take you to an acid-base solutions simulation. Click download.

3. First, we will study the solutions under the "Introduction" tab.  To measure the pH, simply click on the gray box labeled "pH" and drag it into the solution.

4. Finally, you create your own acids and bases using the "Custom Solution" tab.

Water

The concentration of H₃O⁺ ions is _________ than OH^- ions.  Therefore the pH of the solution is ____.

Strong Acid

The concentration of H₃O⁺ ions is _________ than A^- ions.  Therefore the pH of the solution is ____.

Weak Acid

The concentration of H₃O⁺ ions is _________ than A^- ions.  Therefore the pH of the solution is ____.

Strong Base

The concentration of M⁺ ions is _________ than OH^- ions.  Therefore the pH of the solution is ____.

Weak Base

The concentration of M⁺ ions is _________ than OH^- ions.  Therefore the pH of the solution is ____.

Custom Solutions

1. For a weak acid, what is the pH of a 0.01 mol/L solution?

2. What concentration of H₃O⁺ ions would you need for the solution's pH to be 6.50? (First use the sliding scales to manipulate the concentration and strength of the acid to the desired pH. Then use equilibrium view to find the [H₃O⁺].)

3. How would you decrease the pH of this solution to 5.00? 

4. For a weak base, what is the pH of a 1.000 mol/L solution?

5. What happens to the solution's pH when you decrease the concentration of OH^- ions? 

Circular Motion Simulation

Use the formula  F(ac)  =  M X v squared/r    to design five circular motion word problems with solutions on the backside.   Check each using the simulation   Hand in the 5 problems on a clean sheet of paper at the end of the period.

http://www.physicsclassroom.com/Physics-Interactives/Circular-and-Satellite-Motion/Uniform-Circular-Motion/Uniform-Circular-Motion-Interactive

The units for v should be m/s,  and must be between 10-20 m/s,   for ac should be m/sec squared, for Force in Newtons   and for radius in meters, between 10-60  and for mass in kgs from 1-20.