00:01
Problem we have an escalator that has a velocity of 0 .6 meters per second.
00:08
I mean on that the height of each individual step in the escalator is 0 .125 meters.
00:19
The length of each little step is 0 .25 meters.
00:24
And we know that in total there's 32 steps.
00:29
We'll say n, we'll call that end.
00:31
I want to find the power necessary to lift somebody that has a mass of 150 kilograms.
00:43
Since we're dealing with power, you know that power is equal to force times velocity.
00:50
But here, the velocity is actually in the y direction, right? because the velocity is going up the escalator.
00:58
So we know that these have components.
01:00
We have v of x.
01:01
And in the y direction we have v y.
01:06
So to find v y, you can say sine theta is equal to vy over v.
01:15
So then vy is just that velocity times sine theta.
01:23
Now let's plug this back in for power.
01:26
So we have power is equal to force times velocity times sine of theta.
01:36
So to find a value for sine of theta, we need to know the dimensions of the escalator...