now I want you to make a prediction in
my left hand I have a standard science
basketball and in my right hand a 5
kilogram medicine ball if I drop them
both at exactly the same time which one
will hit the ground first ah this is the
chick quad isn't it heavy we'll go down
first
well yeah it'll drop faster they'll bite
through the ground the same time you're
actually would have thought they started
would get faster give me a yeah maybe
it's that maybe this one here so you
reckon though this will be faster be
faster so why does that make it go
faster because it the white pulls a dam
quicker what are we measuring when we
say oh it's heavier what are we feeling
grab the D come on yeah objects being
pulled to the earth I guess ok so which
of these objects is being more pulled
for the earth it's that one the black
one all right well here's what we're
gonna do I want you to hold both of
those above your head really
Nannie down the count of 3 right 3 there
one look at the same time do exactly the
same time then at the same time was that
what you expected to see no so what do
you make of it I need to go read more
books magic gravity's gonna pull it the
same right no matter how heavy or how
light it is but gravity is how late or
how heavy something is it's one big mess
tomorrow there must be some force that's
dragging down and actually actual weight
fits and lean doesn't matter how many
lose mass or something care about what
someone's like the white holds it back
in a way even though that doesn't seem
expensive I think you might be hitting
on an interesting point their weight
holds it back now it's not actually
weight that holds it back but inertia
that's the tendency of matter to
maintain its state of motion so to
remain at rest if stationary or to
continue with constant velocity when in
motion what's the big idea big idea is
this one has more mass so it's got more
weight but you can clearly feel there's
also got more inertia which means also
more sluggish but it tends to resist
acceleration so that greater force is
required to accelerate it at the same
rate as this ball like a heavy car
trying to accelerate like a heavy car
trying to accelerate you need more force
to get it going
yeah exactly so what does all that mean
well the force on the medicine ball is
greater than the force on the basketball
but it has more inertia and what's
really important is that the ratio of
force to inertia is the same for all
objects so everything accelerates at the
same rate and lands at the same time
crashes look because it's conducting the
heat to the ice cube now it's faster
right yeah most of us have been
captivated by one of these a slinky so
why doesn't the Space Station come
crashing into the earth