Hollow Strength Student Worksheet

ADVERTISEMENT

“HOLLOW STRENGTH”
Background:
When we think about what a bone is made of, we usually imagine it to be a dry and hard
substance that doesn’t appear to be ‘living’ in any way. In fact, the bones in our bodies are filled
with living material. There are blood vessels which run near the surface of the bone, and two
layers of bone types, compact bone and spongy bone. Often there is a jelly-like area in the
center of the bone, which is called the bone marrow. Bone marrow produces the body's blood
cells. Red blood cells carry oxygen around the body and white blood cells fight infection within
the body.
Our long bones are hollow, and their cross sectional shape is a circle. Engineers agree that this
structure is difficult to bend or twist. When we walk, run or lift objects, our bones do flex a little,
but their basic shape helps to prevent them from grossly deforming or collapsing. If the central
cavity of long bones were solid, bones would be considerably heavier, requiring much larger
muscles to create movement. The added weight of extra muscle would make it difficult to move.
Activity Procedure Part 1:
Materials
1. Students will roll up a sheet of paper into a cylinder with
Computer Paper (8 1/2 X 11)
a diameter of 1 inch. Students will make a total of 4
Tape
cylinders/ paper bones.
Paper Plates
2. Students will stand the paper bones up on their ends,
Weights (wooden blocks -
placing a paper plate on top of the bones.
all the same size and shape)
3. The teacher will ask the students to explain what is
Scale
happening. (The hollow rolls are supporting the plate.)
Student Worksheet
4. The students will begin to add weights (wooden blocks)
to the plate.
5. The students will count how many blocks the plate can
hold before it collapses the bones.
6. The student will chart their results on the Student Worksheet.
Activity Procedure Part 2:
7. Students will roll up 4 more sheets of paper as tightly as possible, so there is little to no
hollow section.
8. The students will stand these “paper bones” just as before and place the same paper plate on
top of them.
9. The students will begin to place weights on the top pf the plate until it collapses.
10. The students will conclude what happened and chart their results on the Student Worksheet.
11. The teacher will explain that hollow bones were able to support more weight. Having a
hollow center gives the bones a better design and makes them stronger. The large bones in
our body are also hollow, which makes them strong so they can support more weight , but
light, so it takes less energy to move them.

ADVERTISEMENT

00 votes

Related Articles

Related forms

Related Categories

Parent category: Education
Go
Page of 2