00:01
In this video, i'm going to be looking at a perfectly elastic one -dimensional collision between two objects.
00:07
Okay, so we have one object sitting over here initially at rest.
00:13
Okay, and i'll call this object two.
00:16
We have object one coming in with some velocity directly towards object two.
00:24
They're going to collide and rebound, and we want to look at their motions after the collision.
00:31
Okay, so i'm going to call the direction of initial motion, this direction, the positive x direction.
00:37
So this will be negative x.
00:41
Okay, let's look at some values we have for initial velocities and masses.
00:48
Okay, so mass 1 equals 0 .450 kilograms.
00:57
Mass 2 equals 0 .950 kilograms.
01:07
The initial velocity of object 1 is 5 .68 meters per second.
01:17
Okay, and the second object is at rest, so each initial velocity is zero.
01:22
And what i want to find are the speeds and directions of each of these objects after the collision.
01:30
Okay, so i'll call that v1f and v2f.
01:36
Okay, so what do those two equal? you may recognize this as being a conservation of momentum problem.
01:46
Okay, also since we have a perfectly elastic collision, mechanical energy is also going to be conserved.
01:53
Okay, we're going to be, there's no potential energy terms here.
01:56
So our kinetic energy will be conserved.
02:00
So our kinetic energy before the collision will be equal to our kinetic energy after the collision, just like our momentum before the collision will be equal to the momentum after the collision.
02:12
So let's look at momentum first...