Download part b: push-ups (chest and arms)

Work and Power Lab
NAME ___________________________
How Fast Can You Do Work?
I. PURPOSE: In this activity, we will experience the concepts of Work and Power using
simple classroom materials. Please complete the following activities in your group.
II. MATERIALS:Spring Scale, Scale, Mass, Meter Stick(s), Stopwatch, Calculator
III. DEFINE the following, include the equation used to calculate the term if it applies.
1) Work: ________________________________________________________
2) Power: ________________________________________________________
3) Newton: _______________________________________________________
4) Joule: _________________________________________________________
5) Watts: _________________________________________________________
6) Horsepower:____________________________________________________
IV. PROCEDURE ONE
Let the FORCE Be With You…
Measured Force
1. Select an object (wood block, etc.) and use the Spring Scale to “lift” the object.
Determine how many Newton’s your object weighs.
____________ N
Calculated Force
2. Determine the mass of the object using a triple beam balance: ____________ g
3. Convert the mass of the object to kilograms.
____________ kg
4. Calculate the Force (weight) of the object using Newton’s 2nd Law:
Force = mass x acceleration of gravity
Force (weight) = ____________ kg x ___________ m/s2 =
____________ N
5. Compare your measured Force (see #1) with the calculated Force (#4). Analyze any
similarities or differences you see.
__________________________________________________________________________
__________________________________________________________________________
__________________________________________________________________________
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V. PROCEDURE TWO
How Fast Can You Do Work?
PART A: ROLL-UP (WRISTS AND FOREARMS)
1) Measure and record the mass (kg) of the object that is to be lifted.
2) Attach a mass to the end of a string.
3) Measure and record the distance (m) from the hanging mass to the
top of the string where the string goes into the dowel rod.
4) Measure and record the time (s) as to how quickly you can raise the mass by rolling the
string onto the dowel rod lifting the mass as you twist your hands.
5) Calculate the force (N), work (J), power (W) and horsepower (hp) that was produced
from this activity and record your data in the table below.
F= mxa
Mass (kg)
Distance (m)
Force (N) = kgm/s2
Time (s)
W=Fxd
Work (J) = Nm
P=
W
t
Power (W) = J/s or Nm/s
hp =
P
746 w
Horsepower
(1 hp = 746 W)
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PART B: PUSH-UPS (CHEST AND ARMS)
1) In an “up/ready push-up position”, place your hands on the scale to determine the amount
of your body’s mass you will be pushing. Record the data in kg in the data table below.
2) Measure the distance (m) from the floor to the front of your body (chest).
a. You can do as many push-ups as you like (5 push-up minimum). REMEMBER TO
MULTIPLY THE DISTANCE BY THE NUMBER OF PUSH-UPS YOU DO IN
ORDER TO GET THE TOTAL DISTANCE IN METERS. RECORD THE TOTAL
DISTANCE IN YOUR DATA TABLE.
3) Measure and record the amount of time (s) it takes to perform the 10 push-ups.
4) Calculate the force (N), work (J), power (W) and horsepower (hp) that was produced
from this activity and record your data in the table below.
F= mxa
Mass (kg)
Distance (m)
Force (N) = kgm/s2
Time (s)
W=Fxd
Work (J) = Nm
P=
W
t
Power (W) = J/s or Nm/s
hp =
P
746 w
Horsepower
(1 hp = 746 W)
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PART C: CURLS (FRONT OF UPPER ARMS/BICEPS)
1. Use the scale to measure and record the mass (kg) of your object.
2. Hold the weight in your hand that you will be using for this activity. Let your arm hang
down in a relaxed, ready position.
3. Measure the distance(m) from this starting position to its final position as you curl your
arm upward, stopping at your shoulder. MULTIPLY THE DISTANCE OF ONE ARM
CURL AND MULTIPLY IT BY 10 TO GET THE TOTAL DISTANCE IN METERS.
RECORD THE TOTAL DISTANCE IN YOUR DATA TABLE.
4. You will be doing 10 arm curls in as little time as possible. Measure and record the total
time (s) it takes to perform the 10 arm curls.
5. Calculate the force (N), work (J), power (W) and horsepower (hp) that was produced
from this activity and record your data in the table below.
F= mxa
Mass (kg)
Distance (m)
Force (N) = kgm/s2
Time (s)
W=Fxd
Work (J) = Nm
P=
W
t
Power (W) = J/s or Nm/s
hp =
P
746 w
Horsepower
(1 hp = 746 W)
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PART D: STAIR RUN (LEGS)
1. Use the scale to measure your weight in pounds, then convert to kilograms. Record the
total mass (kg) in the data table below.
2. Determine the distance from the bottom of first floor to the top of the second floor.
3.
To do this, measure the height of each step and count the number of steps between
the first and second floor.
4. Record the total distance (m) in your data table.
5. With a stopwatch, measure and record the time (s) it takes you to get from the first floor
to the second floor.
6. Calculate the force (N), work (J), power (W) and horsepower (hp) that was produced
from this activity and record your data in the table below.
F= mxa
Mass (kg)
Distance (m)
Force (N) = kgm/s2
Time (s)
W=Fxd
Work (J) = Nm
P=
W
t
Power (W) = J/s or Nm/s
hp =
P
746 w
Horsepower
(1 hp = 746 W)
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VI. ANALYSIS QUESTIONS:
ANSWER THE FOLLOWING QUESTIONS IN COMPLETE SENTENCES.
1) Identify the two variables that affect work?
2) Which activity required the most work? Explain this using the two variables that affect
work from answer #1.
3) Which activity produced the most power? Explain why.
4) If you wanted to produce more power, what could you do to maximize power?
5) Would you be doing any more work by going up the stairs twice as fast? Explain.
6) This lab should have led you to a point of better understanding of work and power. It is
now your chance to pull it all together by writing a well written, thoughtful paragraph
about how the terms below are all interrelated. It should make logical sense and
include all of the following terms. (Please write your paragraph on a separate piece of
paper and attach to the lab packet.)
Work
Kgm/s2
Force
Power
Joule / second
Distance
Joule
Newton
Time
Newton meter
Horsepower
Watts
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