[Music]
it's um sometime
[Music]
what if lions ruled the world
no ways i'm some will always rule the
world
oh i'm some firstly if lions ruled the
world lions have massive beards people
may now start growing long beards in
order to impress the lions
secondly if lions ruled the world
everyone will now have to learn how to
roar like a lion
hmm
thirdly if lions ruled the world
salons may be busy grooming lions we may
have to start cutting our own hair
fourthly if lions ruled the world lions
are extremely fit and muscular everyone
may try to build their muscles in order
to impress the lions
[Music]
fifthly if lions rule the world keeping
lions entertained will not be an easy
task entertainers might be for a
different planet
lastly if lions ruled the world dentists
may start fainting after having a look
at lion's sharp teeth
[Music]
to buy um some merchandise visit
umsum.com
topic gravitational force
why do you weigh less on the moon
hey what are you doing it is not
possible you cannot fly on earth please
listen
[Music]
look i had warned you
now why don't you try the same activity
on the moon
there you will weigh much less and thus
you can fly short distances
[Music]
huh
see i was correct
do you know why you weighed less on the
moon
to understand this we need to first
learn about weight
no not those weights
weight is the force with which an object
is pulled towards the center of the
earth or any other celestial body this
force is called the gravitational force
greater the gravitational force exerted
by the celestial body or will be the
weight of an object present on it
so does this mean that the moon exerts
less gravitational force than the earth
bingo you are right but do you know why
this is because gravitational force is
directly proportional to the mass of an
object
[Music]
greater the mass greater will be the
gravitational force exerted by it and
thus more will be our weight
as the moon has lesser mass than the
earth it has a weaker gravitational pull
and hence we weigh less on the moon
topic sublimation
why do moth balls disappear over time
[Music]
wow you have a nice collection of
clothes
but have you kept mothballs to protect
them yeah yeah
i'd kept them a few months back below
these clothes
hey where did the moth balls go i placed
them right here
did you steal them no no
i haven't stolen anything mothballs
disappear over time do you know why it
is because of a process called
sublimation during sublimation a solid
on heating converts directly into vapor
without passing through the intermediate
liquid state
don't lie how is that even possible
see i also hit a burger here many days
ago it did not disappear
oh gross just throw that burger in the
dustbin
not all substances sublimate mothballs
are made up of nap filling naphthalene
has very weak intermolecular forces
because of these weak forces the
mothball which is made up of naphthalene
sublimates that is it changes its state
from solid to vapor now this vapor is
either absorbed by the fabric or it
escapes into the atmosphere causing the
mothballs to disappear over time