LAB

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LAB: Do Some Work!
Before we begin, please be sure to read the lab safety rules listed below. They are the exact rules
which you all agreed to follow when you signed and returned the Lab Safety Contract at the
beginning of this year. Please read them carefully to remind you as to what is expected of you in
our labs.
1. Dress appropriately. Appropriate attire includes:
a. Shirts that cover your torso, back, and upper arms
b. Pants that fall below the knee
c. Safety goggles (will be provided when needed)
d. Gloves (will be provided when needed)
e. Shoes completely covering the foot
2. No jewelry is to be worn at any time
3. Long hair is to be tied back in a ponytail
4. Fooling around of any kind WILL NOT be tolerated. Follow directions and complete the lab.
5. Come prepared. Before you come to lab, be sure to complete the pre-lab and read the
procedure carefully. If the pre-lab is not completed, you will automatically lose ten points.
Please notify me of any extenuating circumstances immediately.
6. If any glassware breaks or equipment malfunctions, please notify your instructor. DO NOT
take any other action.
7. When working with circuits:
a. Have the instructor check the circuit prior to turning on the power
b. Be sure the power is off when making changes to the circuit
c. Do not connect the terminals of a power supply with a wire
8. Do not lift an apparatus that may be hot with your bare hands. Use tongs.
9. Return all equipment and clean your station
10. Failure to follow any of the above rules will result in removal from the lab and a 0 for the
assignment.
PRE-LAB
Complete the following prior to our lab.
1. Define Energy, Work, and Power in complete sentences.
2. Define the Work-Energy Theorem in a complete sentence.
3. Janine pushed a 1 kg box so that it was sliding across a wooden floor. The box’s initial
velocity was 4 m/s but it eventually slowed down to 2 m/s. How much work was done? Is it
positive or negative work? How do you know? What was the force doing this work?
4. Mick’s truck can go from 0 to 60 mph in 3 seconds. Carla’s truck has a 40 horsepower
engine and can go from 0 to 60 in 12 seconds. How much horsepower is Mick’s engine?
How many watts is Mick’s engine? (1 hp = 745.7 W)
LAB
Greetings class! Before we begin the lab, please break into your lab groups for today as specified
on the board.
Each group will have the following supplies:
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Triple beam balance
3 objects of unknown mass (labeled as “object 1,” object 2,” and “object 3”)
Dowel rod with string tied to it
Stopwatch
Meter stick
Procedure:
1. Record the mass of each object to the nearest 0.01 g in the data table provided. Convert to
kilograms and record in the appropriate column.
2. Find and record the weight of each object in Newtons. Use 9.81 for the acceleration due to
gravity.
Each member of your group must complete the following and record their own results.
3. Tie object 1 to the free end of the rope attached to the dowel rod.
4. Measure the distance between the dowel rod and object 1. Record to the nearest 0.01 meter.
5. Make sure that someone in your group has the stopwatch ready as you must time the next
step.
6. As fast as you can, twist the dowel rod so that the string wraps around it and object 1 is
raised as much as it can be. Record the time it took to the nearest .01 seconds.
7. Repeat steps 3-6 for objects 2 and 3.
8. Once everyone has done this with all 3 objects, return all equipment.
9. Complete the necessary calculations to complete the table.
10. Compare your results with your group.
11. Answer analysis questions.
12. Write a report to submit with the data sheet and analysis questions. It must be at least 2 pages
in length and will be due the day after the unit test.
Object 1
Object 2
Object 3
Mass (g)
Mass (kg)
Weight (N)
Distance from rod
to object (m)
Time it took to lift
the object (s)
Work (J)
Power (W)
Power (hp)
Analysis Questions:
1. What differences did you notice between you and your groupmates? Why might there have
been differences at all?
2. Which object took the least amount of power for you to lift? Why?
3. If you lifted object 1 twice as fast, what would the power be based on your results? Why?
4. Explain your results in a concise paragraph, explaining any possible errors. Use the following
terms:
Joule
Power
Work
Energy
Joules/second
Newton
Watt
RUBRIC
Level 1
Student did not
follow procedure and
seemed to pay little
attention to the rules
established for the lab
(0 pts)
Level 2 (4 pts)
Student followed
basic procedure, but
it was clear they did
not take as active as a
part in the lab as they
should have
(1 pt)
Level 3 (6pts)
Student followed
procedure and was
active in their work
with the lab group
they were assigned
(3 pts)
Data/Calculations
Student is either
missing most data or
did not report it in an
acceptable format
(2 pts)
Student reported all
or most data but their
calculations were not
clearly explained in
the report and/or
were incorrect
(4 pts)
Student reported all
data in the data table
and on the lab report
and clearly showed
each of their
calculations in the
report
(6 pts)
Analysis Questions
Student did not
answer or put
noticeably little effort
into answering
analysis questions
(2 pts)
Student’s responses
showed some thought
and consideration for
the question asked
(4 pts)
Student demonstrates
a proficient level of
critical thinking,
using the questions to
think beyond the lab,
and discusses
responses in report
(8 pts)
Objectives
Student did not refer
to any objectives in
the report
(0 pts)
Student’s listed
objectives were
vague and/or not
applicable
(1 pt)
Student lists clearly
and appropriate
objectives in report
(2 pts)
Analysis and
Conclusion
Student was either
missing this portion
in their report or did
not provide sufficient
content for it
(2 pts)
Student’s analysis
and conclusion
consisted primarily of
observations with
some analysis
(6 pts)
Student’s analysis
and conclusion make
inferences based
upon observations
and what we covered
in class
(10 pts)
Professionalism
Presentation
Report is
disorganized and/or
unreadable
(0 pts)
Report is readable but
is not in the desired
format
(1 pt)
Report is formatted
correctly and is wellorganized
(2 pts)
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