3. An object at rest tends to stay at rest and an
object in motion tends to stay in motion with the
same speed and in the same direction unless
acted upon by an unbalanced force.
What
does that
means?
4. An object in motion
wants to stay in
motion, and an object
at rest wants to stay
at rest.
This is also called
INERTIA
5. The car is at rest, and it is going to stay at rest
until a force gives it a push.
6. Now that is moving, it will continue to move
until another force stops it.
Friction
7. The best place to test inertia is in Space, why?
In outer space there is no
air, or anything else to
create friction. So moving
objects will keep moving
forever, and objects that
aren't moving will stand
still forever.
8. •The crash dummy is not wearing a seat belt
and is moving along with the car.
•Both the car and the dummy are moving at,
say 60 mph.
•When the car hits the cement road divider, it is
stopped (an outside force stops it from
moving).
•The crash dummy, however is not so lucky.
Since he is not wearing a seat belt and is not
connected to the car, he will continue to move
at 60 mph. This means he will go flying out
through the front windshield.
•The dummy will fly through the air until he hits
the ground.
•This is because the earth's gravity stopped
him from moving any further.
•If this collision had happened in zero-gravity,
in a vacuum, the dummy would theoretically
keep on hurtling away from the car at 60 mph.
