Chapter 3 - Work and simple Machines

A. RE pp. 41-42: Before You Read, 1. Identify, 2. Calculate, 3. Infer

B. Work (Joules) = Force (Newtons) X Distance (meters)

1. Force = 5 Newtons, Distance = 8 meters, Work = ____ Joules?

2 Force = 10 N, Distance = 10 m, Work = ___ J?

3. Distance = 15 m, Force = 20 N, Work = ___ J?

4. Work = 30 J, Distance = 6 m, Force = ___ N?

5. Work = 55 J, Force = 5 N, Distance = ___ m?

C. RE: C3S2 – Before You Read,

 Calculate, 2. Describe, 4. Identify, 5. Evaluate

D. R.E.: p. 47 “Friction”, 4. Identify, 5. Evaluate

E. - Before You Read, Identify Simple Machines, 1. Evaluate, 2. Calculate, 3. Explain, 5. Analyze 

- p. 54: After You Read #1,2,3

- Add the Mini Glossary words and definitions to your Science Notebooks Glossary

 

 

LAB #4 – Simple Machines Help Us

LAB #4 – Simple Machines Help Us

Problem: How do the various simple machines help us?

Hypothesis:

Materials: various simple and compound machines

Procedure:

Results:

Name of the object					Purpose of the object		What kind of simple machine/s is it?	Draw a picture of the object
1. Plastic drink top
2. chemistry tongs
3. cooking thermometer
4. scissors (2)
5. light bulb and clamp (3)
6. plastic car (2)
7. spray bottle (2)
8. staples
9. clip on clipboard
10. flashlight
11. tape and dispenser (2)
12. rolling pin
13. nails (on wall)
14. screw (in wall)
15. stairs
16. stapler
17. triple beam balance (3)
18. crazy coaster track
19. cabinet drawer track
20. wheel on push cart
21. blinds
22. hammer (2)
23. test tube holder
24.
25.
26.
27.
28.
29.
30.

Analysis:

1) Explain: How do simple machines make our lives easier?

               

2) Identify and Infer: Pick three of the objects from the lab and explain how it would be like without them?  How would you accomplish the tasks they help us with without them?

3) Go to your data table and label the fulcrum for each of your levers.

4) Synthesis: Design your own compound machine; use at least 4 different simple machines.

                

5) Analysis: What is the relationship between the simple machines in this lab and ones found in your home?  

Conclusion

What was your problem?

Restate your hypothesis.  Was it right? wrong?  why or why not?

What did you learn in this lab?

What did you like about this lab?

What were some challenges you had to deal with?

What could you do next with this problem?  What other tests could you perform?

Write down any other additional thoughts, observations, inferences, etc.

Friction!!! with Bill Nye

Watch the Bill Nye video on Friction to prepare for tomorrow's quiz!

Lab #3 – Calculating Work

Lab #3 – Calculating Work

Work = Force x distance

Work = (Force)(Distance)

W = Fd

Problem

How can a ramp help us pull a heavy object up to a greater height?

Hypothesis

Skip 3 lines here

Materials

Ruler, chair, ramp (inclined plane), weights, spring scale, various metallic objects

Procedure

Results

A.Work done without ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight	__N	__cm	___J
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

B. Work done with ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight	N	cm	J
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

 Make another Hypothesis: Use your hands to feel the sandpaper.  Which of these will cause more work to be done on the weights? 

C.Work done with sandpaper on ramp

Object	Force (Newtons)	Distance (cm)	Work (Joules)
20 g Weight
50 g Weight
100 g Weight
200 g Weight
500 g Weight
Metal Object

Length of ramp = ___cm

ANALYSIS

1)   Construct a line graph for results A, B, and C on the same coordinate plane.  Label the x-axis weights (grams) and label the y-axis work (Joules). 

2)   How did the weight (force pulling down) affect the amount of work done on the object?

3)   Compare/Contrast the trial with the least amount of work to that with the most amount of work.

4)   Part 1 (A,B): What is your Independent Variable?

5)   Part 1 (A,B): What is your Dependent Variable?

6)   Part 1 (A,B): What are your Constants?

7)   Part 2 (B,C): What is your Independent Variable?

8)   Part 2 (B,C): What is your Dependent Variable?

9)   Part 2 (B,C): What are you Constants?

10)               Make an inference: Which would increase the friction of the object you are pulling, adding oil to the ramp or glue?  Why would you expect this?

Conclusion

What was your problem?

Restate your hypothesis.  Was it right? wrong?  why or why not?

What did you learn in this lab?

What did you like about this lab?

What were some challenges you had to deal with?

What could you do next with this problem?  What other tests could you perform?

Write down any other additional thoughts, observations, inferences, etc.