00:01
In this example, i'm going to be looking at the relationship between power and energy.
00:06
Okay, so what we have is a water turbine.
00:10
We have water flowing into the turbine at a rate, i'll call that rate, water of 3 ,000 kilograms per minute.
00:27
And this water is coming from a height of 120 meters.
00:35
So say it's water falling over a dam, a dam is 120 meters high falling into this turbine.
00:42
And what we want to do is find the power output of the turbine, assuming it has an efficiency of 80%.
00:52
Okay, so how do we do this? first, i want to find the power into the turbine, and then i can use that with my efficiency to find the power out.
01:01
How do we find power in? power equals, we know that equals work over time.
01:11
And we know that work equals force times distance.
01:17
So that becomes force times distance over time.
01:21
And we know our force equals mg.
01:28
Let me put d in there.
01:31
All right.
01:32
Now this seems like it's not going to help us much.
01:35
But it does because we're given the rate of flow, which is just mass per time.
01:41
All right...