00:01
We are given a height, which i'm going to call y sub 1, of 9 .1 meters.
00:12
And then we're given vector notation, which basically means that v sub 1 is 6 .1 meters per second, v .y 1, and then v .x1 is 7 .6 .1 .5 .2.
00:28
And then v .x1 is 7 .6.
00:33
Meters per second but there's no acceleration in the x direction so that's going to be v x all the time 7 .6 meters per second per second okay what's the maximum height well um v at the peak v y at the peak is going to equal zero which is is, well, let's do this.
01:24
V squared at the peak equals v1, vy1 squared, plus 2g.
01:39
And then we're going to need delta y to the peak.
01:45
So delta y to the peak is going to equal.
02:01
Vy1 squared over 2g.
02:07
I really should put a minus sign here.
02:10
Vy1 squared over 2g.
02:12
So we'll put that into a calculator.
02:17
Move this down.
02:18
So, oops, that didn't work.
02:22
Good us.
02:24
My desmos window is gigantic.
02:26
I don't know why.
02:29
Oh, my goodness.
02:32
Okay, i need to get this thing smaller.
02:34
That was crazy large.
02:41
Okay.
02:46
Vy1, well, let's just put in all the information that i know.
02:49
Y1 equals 9 .1.
02:54
V sub y1 is 6 .1, and v.
03:10
Sub x is 7 .6.
03:16
Oops.
03:20
Okay.
03:21
So now, now, v sub y1 squared, is up in there? b sub y1 squared over 2g.
03:56
Oh, i didn't put in g yet.
03:59
G equals 9 .8.
04:02
That's what the book likes to use here.
04:06
Okay.
04:07
I'm going to move that up because i like things to be neat, even in my calculator.
04:13
Declare my variables first.
04:18
Gee.
04:19
Okay, so that would be 1 .90 meters.
04:33
So, to what height does it reach? well, y at the peak is going to equal y1 plus delta y at the peak.
04:47
So putting that into a calculator, y sub p equals y sub 1 plus, and then i didn't really give this a name.
05:12
I'm just going to call it y sub, because i can't put a delta in, to the best of my knowledge, 15, because i'm never going to need it again.
05:20
I don't think i'll ever need that again.
05:22
So y some 15.
05:26
Okay, so that's going to be 11 meters b.
05:41
Now for the second part, i would like to know time to the peak.
05:48
So, vy peak, which again is zero, is going to equal from the beginning, vy zero, which is zero.
06:01
No, no, no.
06:10
Oh, we don't know vy at the beginning.
06:14
So let's try this.
06:18
Vy to the peak is going to equal vy1 minus g times t.
06:44
This isn't really t to the peak...