# Average vertical velocity

1. Oct 30, 2007

### nblu

Q: A firefighter climbs up a 10.0m ladder leaning against a vertical wall.
The ladder makes an angle of 25.0 degrees with the wall. The firefighter reaches
the roof in 15.0s

a) What is the height of the wall? 9.10m
b) How far is the base of the ladder from the wall? 4.23m
c) What is the firefighter's average vertical velocity?

I have completed a) & b) as those were straight-forward questions by using Trig.
However, I got stuck on c). I understand that the average vertical velocity is
$$\Delta$$d/t, t would be 15.0s but I'm not sure what the value of the d would be.

Thank you

2. Oct 30, 2007

### Kurdt

Staff Emeritus
Thats a good question. I think you're probably confused as to whether the distance is the length of the ladder or the height of the wall. Personally I'd say height of the wall but this is a subjective issue of semantics. If you have time I'd clarify it with whoever set you the question.

3. Oct 30, 2007

### tyco05

If it says average vertical velocity then surely it has to be the height of the wall.

4. Oct 30, 2007

### nblu

Thanks guys, I really appreciate it.
This is a course that I'm taking from adult learning centre.
It's an independent learning so I have to get this done on my own :(

but after getting help from you guys, it really helps me to re-direct from wrong to right.

ANYWAYS!!! after squeezing out my brain I just put a conclusion.
Because its asking for "vertical" meaning the "wall" in this case,
I've had the height of the wall as D and divide it by 15 seconds to get the answer.
I think that makes sense

Many thanks guys :)