Forces and the Egg-citing Egg
Drop
One of the most important parts
of physics is being able to
understand forces.
A force is
something
that
changes
an
object’s shape or movement. This
week, we’ll study one of the most
important forces in our lives:
GRAVITY. Gravity is a force that
pulls objects towards each other.
It is the force that makes objects fall to earththings are attracted to and pulled towards the
center of earth.
You can think of a force just
like this, as a push or a pull.
Another important force is DRAG.
Drag comes
from air pulling on moving objects, like the forces
you feel when you hold your hand outside the window
of a car.
What happens when we drop a flat and
crumpled piece of paper at the same time? The flat
paper feels more drag from the air.
Drag is the force that makes it move
more slowly than the crumpled paper.
Drag is also the force that makes a
parachute work; air gets caught in the
parachute and slows the person down.
Have you ever dropped an
egg?
Even if you haven’t,
it’s
easy
to
guess
what
happens.
The
egg
almost
always breaks when it hits the
hard floor.
But what would
happen if you dropped the egg
onto a large feather pillow?
If the pillow were large and soft enough, the egg
would not break in fall. Why is this?
As an egg falls towards the floor, it begins to
travel faster and faster.
When it slams into the
floor, the egg is stopped almost immediately. This
force of the floor against the eggshell is too
large, so it breaks. Unlike the floor, a pillow is
soft and cushions the fall of the egg. This allows
the egg to stop slowly, decreasing the force
against the egg so it doesn’t break.
Can you construct an egg-holder
survive being dropped to the ground?
that
will
Building an Egg Holder
1. You will build a container for your egg that will
survive being dropped from five feet or more above
the ground.
2. You can use one piece of cardboard, one piece of yarn,
one sheet of newspaper, and two feet of masking tape
to build a device for your egg to help it land safely.
3. You may want to build a box, a bed, or even a
parachute for your egg. Remember to think about
what we learned about gravity and air resistance.
4. You get two eggs and two zip lock bags to keep them
in to prevent a mess in case they break. The bags are
just to stop mess, so press all the air out of your bag
before you begin. The same set of materials must be
used for both eggs, so give it your best effort with
your first egg! You won’t be getting any more tape.
When everyone is done making his
or her egg-holder, the
competition will begin!
You and your HP mentor will be an egg dropping team.
Drop your egg, starting at five feet. If your egg breaks
when you drop it, your team is out!  If it survived, move
the egg 1 foot higher and drop it again. The person whose
egg survived the highest drop is the winner.
Egg-stra Fun with Physics
1. What would make one object have more air resistance than
another?
2. Why would something not break if it fell on a pillow as
compared to the bare floor?
3. Did your egg break? Why or why not?
4. How many feet were you able to drop your egg before it
broke?
5. Which egg holder design seemed to work best? Why do you
think it worked?