ShmoopTube

00:00

Thank you We sneak And here's your shmoop du jour

00:05

brought to you by any elastic collisions which occur when

00:09

there's a collision and kinetic energy is lost Elastic collisions

00:13

on the other hand are just they're physicist speak for

00:15

rubber band fights Those are awesome Okay why is kinetic

00:20

energy lost in in elastic collisions If energy is always

00:26

conserved and hear the potential answers logical good questions here

00:33

All right so what does happen in an inn elastic

00:36

collision Well we know that the law of conservation of

00:39

energy can't be broken which is enough to eliminate option

00:42

b There are no exceptions the laws of physics that's

00:44

why they're called laws people and not suggestions of physics

00:48

and option d yeah that's a lawbreaker too Conservation of

00:51

energy isn't just on paper it's a real life things

00:54

so see eddie but kinetic energy isn't always transferred to

00:58

the other object in an inn elastic collision either if

01:01

we throw a spitball at a wall and it sticks

01:03

there while the wall isn't moving So it hasn't gained

01:06

any kinetic energy which rules out eh So we're left

01:09

with option c it's the correct answer The kinetic energy

01:13

is transformed into a different state Take a look at

01:16

captain sticky here jumping from a trampoline onto a wall

01:19

He certainly doesn't have any kinetic energy anymore but since

01:23

he stuck up there he now has potential energy right

01:26

He could fall and kinetic energy can also be transformed

01:29

heat energy sound energy and other forms of energy too

01:33

Now most real world collisions are at least partially in

01:36

elastic after almost things don't perfectly transfer kinetic energy When

01:40

they collide there's friction which creates heat energy and objects

01:45

can get deformed which takes energy too Think of a

01:48

basketball if we bounce a basketball on concrete from a

01:51

height of five feet it won't bounce five feet high

01:54

it's partly because of gravity and partly because when the

01:56

ball hits the ground it compresses slightly then returns to

01:59

its normal shape Well that's kinetic energy Taking a different

02:02

form is a type of potential energy This is the

02:05

same type of potential energy created when we pull a

02:08

rubber band back like that And when that rubber band

02:10

smack someone in the face or the rear that's called 00:02:14.11 --> [endTime] an act of war it bring it

Full Transcript