00:01
All right, looks like we have a couple of questions here.
00:05
Colton and shannon are 220 feet apart when they begin walking directly toward one another.
00:12
Colton travels at a constant speed of 3 .5 feet per second, and shannon travels at a constant speed of 5 feet per second.
00:22
So we want to let t represent the number of seconds that have elapsed since colton and shannon started walking toward one another.
00:31
Write an expression in terms of t that represents the number of feet.
00:36
Colton has traveled since he started walking towards shannon.
00:43
So let's look at this.
00:44
So we have colton here and we have shannon here.
00:53
And this distance is 220 feet.
01:02
Colton goes 3 .5 feet per second.
01:09
And shannon walks a little bit faster.
01:13
5 feet per second.
01:17
So we want to write an expression in terms of t that represents the number of feet colton has traveled since he started walking toward shannon.
01:27
So for a and b, i've kind of already got it here a little bit.
01:31
So for a, if we want to calculate, so remember t is how many seconds have elapsed since they started walking.
01:44
So for colton, we need to take his speed, 3 .5 .5 .5.
01:51
And so for colton, we need to feet he's going 3 .5 feet per one second and then if we multiply that by t seconds over one this is what is going to give us we're going to get 3 .5 t feet because our units there will cancel just like numbers will and it's very similar for shannon i think this actually is part shannon's going five feet per one second and t seconds over one and we get five t our units there cancel feet so there's part a and part b now we want to write an expression in terms of t that represents the distance between colton and shannon well remember they started out 220 feet apart then we're going to we're going to subtract how many feet colton has traveled, and we're going to subtract how many feet shannon has traveled.
03:10
And that is going to give us the distance.
03:13
We take our initial distance, we subtract how far colton has gone, we subtract how far shannon has gone, and that will give us the distance between the two of them.
03:23
Now, how many seconds after the two started walking will the two reach each other? so what we want to know, we want to solve for t when this distance from part c, the distance between the two of them is equal to zero.
03:44
Because we don't want any distance between them if they're going to reach each other.
03:48
So this is a pretty simple algebraic equation.
03:51
Let me come over here.
03:53
I'm going to have 220 minus 8 .5t.
03:58
That's combining my like terms right here.
04:01
I'm going to subtract, or actually let me add 8 .5t to both sides.
04:11
And so i'm going to get that 220 is equal to 8 .5t.
04:17
And then we divide by this 8 .5 to isolate our t.
04:21
I'm going to have to grab my calculator for that.
04:24
220 divided by 8 .5.
04:27
And i get 25 .88...