Transcript Notes

Chapter 17-Newton’s Laws
Gravity and Motion-The acceleration due to
gravity is the same for all objects on Earth;
this is 9.8 m/s/s
Air resistance (fluid friction) slows down
this acceleration
Terminal velocity: the object falls at a
constant velocity and stops speeding up.
1st Law of Motion
An object at rest or in motion will
continue in that way until another
force acts upon it.
Example: Bowling pins will
continue to sit at the end of the
alley until someone rolls a bowling
ball into them, knocking them
2nd Law of Motion
An object acted upon by a force
will accelerate in the direction of
that force.
a=net force/mass
Force measured in N, or 1 kg m/s2
Example: If you are pushed on a
swing, you go forward, the
direction of the push. Gravity
brings you backwards, the direction
of it’s pull.
3rd Law of Motion
For every ACTION, there is an
opposite and equal REACTION.
You push on a wall, it pushes back at
you with equal force. So, if you walk
into a glass door you didn’t realize
was there, you definitely know it. 
Other examples: Pushing with your
feet off the diving board; pushing a
canoe paddle through water; a
rocket launching from the earth.