8th grade Integrated Science
Standard IV, Objective 3
Title: “Presence of Mind”
Description: Students will use a story about a pulley gone bad to learn about pulleys,
direction of force and mechanical advantage. They will create a cartoon series to
illustrate the story.
Time Needed: 50 minutes
Materials: colored pencils, student sheets, story
Procedures:
1. Make individual copies of the student sheets and a classroom set of the story.
2. Read the introduction on the student sheet and the directions with the students.
3. Read the first paragraph and work with the students to fill in their first cartoon. Make
sure every student understands the starting point.
4. If you have a group of students with ESL or reading difficulties, you may wish to
group them and continue to read with them.
5. Allow students time to work. Towards the end of the period, ask students to pair up
and share their work with a partner or group.
Student Sheet
Name_______________________________
Title: Presence of Mind
Introduction: Simple machines are widely used in construction. A funny story that
may or may not have happened (but could have!) will help you understand how a pulley
works. This information about pulleys will help you understand the story:



A single fixed (attached to something) pulley does not give
a person any mechanical advantage.
A person cannot apply more force to a pulley than they weigh.
A single fixed pulley changes the direction of force
needed to move a load.
As you read the story, see if you can make a mental image
of what is happening. When you are done, you will draw a
series of cartoons to illustrate this story.
Procedures:
1. Read the story “Lost Presence of Mind” carefully, imagining what is taking place.
2. On the back of this paper, use the boxes to draw a cartoon of the story, step by step.
3. In the final box, predict what will happen when the author lost his “presence of mind”
for the last time.
Data: on the back
Analysis:
1. This story was written to an insurance company to explain the injuries that occurred
in the accident. If you were an insurance agent, would you think your company should
pay the bills?
Why or why not?
2. The author started with a good idea, to have a simple machine help him out. What
should the pulley system he used look like? Draw it below:
Conclusion:
Lost presence of mind
This is a copy of an alleged letter written to an insurance company that wanted a
complete explanation from an injured man who had explained what happened with the
words "lost presence of mind".
"I'm a bricklayer by trade. On the day of the accident, I was working alone on the roof of
a new six story building. When I had completed my work, I discovered that I had about
500 pounds of bricks left over. Rather than carry the bricks down by wheelbarrow, I
decided to lower them in barrel by using a pulley which was attached to the side of the
building at the sixth floor.
"Securing the rope at ground level, I went back up on the roof, swung the barrel out and
loaded the bricks into it. Then I went back to the ground floor and untied the rope,
holding it tightly to assure a slow descent of the 500 pounds of bricks. You will note in
block 11 of the accident reporting form that I weigh 135 pounds.
"Due to my surprise at being jerked off the ground so suddenly, I 'lost my presence of
mind' and didn't let go of the rope. Needless to say, I proceeded at a rapid rate up the
side of the building.
"In the vicinity of the third floor, I met the barrel coming down. This explains the
fractured skull and broken collarbone. Slowed only slightly, I continued the rapid ascent,
not stopping until the fingers of my right hand were two knuckles deep into the pulley.
This explains the lacerations of my right hand. Fortunately, by this time I had regained
my presence of mind and held tightly to the rope in spite of the pain.
"At approximately the same time, however, the barrel of bricks hit the ground, and the
bottom fell out of the barrel. Devoid of the weight of the bricks, the barrel now weighed
about 50 pounds. I refer you again to my weight of 135 pounds, in block 11. As you can
imagine, I began a rapid descent down the side of the building.
"In the vicinity of the third floor, I met the barrel coming up. This accounts for the two
fractured ankles and the lacerations to my legs. The encounter with the barrel slowed
me enough to lessen my injuries when I fell into the pile of bricks, and fortunately only
three vertebrae were cracked.
"I am sorry to report, however, that as I lay there in the bricks, in pain, unable to move,
and watching the barrel six stories above me, I again 'lost presence of mind'; I let go of
the rope."