Kind: captions
Language: en
Nearly 350 years ago, Isaac Newton came
up with three laws of motion that govern
how everything moves. There are three
pretty famous laws of motion. And
they're not very complicated, but if I
told them to you as clearly as I can,
you would think that you're
understanding them. But I think you
wouldn't. And the reason is everyone has
ideas about physics and about how
objects move before they're ever taught
anything uh in a science classroom. So
rather than tell you Newton's three laws
of motion, I would like to tell you
Derek's three incorrect laws of motion,
which are the ones I think you're
actually thinking.
So Derek's first incorrect law of motion
is
an object with no unbalanced forces
acting on it will naturally come to
rest.
[Applause]
Derek's second incorrect law of motion
is that an unbalanced force causes an
object to move with a constant velocity.
We could express this in an equation
where the unbalanced force F equals the
mass m times the velocity v. So if you
double the force, the velocity also
doubles.
It's just like being in a car. As you
press on the accelerator, you increase
the force on the car and therefore you
move to a new higher constant speed.
Derek's third incorrect law of motion is
that larger objects apply larger forces
to smaller objects.
When a large truck slams into a car on a
highway, the force of the truck on the
car is much greater than the force of
the car back on the truck.
Or if you think about the Earth and the
moon, the force with which the Earth
attracts the moon is greater than the
force with which the moon attracts the
earth. But remember, this is an
incorrect law of motion.