00:01
So an essential idea here is to think about average velocity.
00:05
The average velocity is the change in height or change in position generally over the change in time.
00:12
And this might remind you of slope, right? it's like rise over run.
00:16
We're just using quantities from physics, namely height and time.
00:21
So let's make a little table that tells us the time and the height.
00:27
So at zero seconds, we have 16 times zero squared.
00:30
That's zero.
00:32
At one, we have 16 times one squared, which is 16.
00:36
We can plug in two as well.
00:39
Let's plug in three for a good measure.
00:43
So how far does this object fall between zero and one seconds? that's a change in 16 feet.
00:52
So that's the answer to part a.
00:55
How about between one and two seconds? well, 64 minus 16 is 48 feet.
01:01
And that's the answer to part b.
01:03
Part c, is interested in us analyzing the average velocity between times two and three.
01:12
Well, the change in height is 144 minus 64 or 80.
01:18
Now we need to divide by the change in time as well, but that's us three minus two.
01:25
So our average velocity is 80 feet in one second or 80 feet per second.
01:31
And note that's only the average velocity starting at time two and ending at time three.
01:35
That interval.
01:37
How about the average velocity for the interval 3 to 3 .01? well, we could plug 3 .01 in, 16 times 3 .01 squared is 144 .96.
01:56
So let's compute our average velocity again, using our formula, the change in height or position would be those two values subtracted...