00:01
Okay, we're given a particle of mass m that's moving along our position vector named r of t.
00:08
So we're going to find our force acting on the particle at time t.
00:13
So force is mass times acceleration.
00:16
Both force and acceleration are vectors.
00:20
So we're going to have to take a second derivative of position.
00:23
So our first derivative will be our velocity.
00:26
Now, when we take our derivatives, notice the 2t inside.
00:29
So we multiply by the derivative of the inside.
00:32
So each time we're going to multiply by a 2.
00:34
So we get that 6 cosine of 2t in the i minus a 6 sign of 2t in the j.
00:43
Our next derivative will be acceleration...