Go Down

### Topic: Mathematical question (Read 693 times)previous topic - next topic

#### Nachtwind

##### Sep 15, 2009, 07:57 am
Ok, please dont laugh, but i am sitting on a physical/mathematical problem i am unable to solve atm (blackout..).

I have a distance (300m) a V0 (0m/s) and a time (60s).
How do i calculate the mean acceleration to reach the 300m in time?
The formula is - if i am not totally wrong - " a = v(t^2)+V0" - but i simply hang myself because of the velocity in the middle part of the term...
Damn, it's been to much time since i was having physics last time, or math..

#### kristina

#1
##### Sep 15, 2009, 08:59 am
It's not stupid to forget, we are all getting older and filling our heads with other things... If you solve X=v0*t + 0.5*a*t^2 with the values you give, you will get 0.16667 m/s^2. But don't blame me if I'm wrong, it's been a while for me as well...

Joachim

#### borref

#2
##### Sep 15, 2009, 09:04 am
If you traveled this distance at a constant speed - the speed would have to be 300m/60s = 5 m/s. To travel the same distance with linear acceleration from stand-still and using the same time, speed at the end would have to be twice that of the constant speed example.

The generic formula for this type of problem is then as follows:

d = vt + (1/2)a(t^2)

d = distance
v = initial speed
t = time
a = acceleration

With initial speed at 0 and solving for "a" you get:

a = d / ((1/2)(t^2))

a = 300 / ((1/2)(60^2)) = 0.17

#### kristina

#3
##### Sep 15, 2009, 09:13 am
I wasn't that far off, I had to check
http://hyperphysics.phy-astr.gsu.edu/Hbase/mot.html

and they calculated the same acceleration.

Joachim

#### Nachtwind

#4
##### Sep 15, 2009, 09:59 am
thanks to you all :0)

#### Nachtwind

#5
##### Sep 15, 2009, 10:54 am
it was university physics, unfortunately not for me, but for someone i tried to help..
But i solved it, thanks. (The parts on electronics were more simple than that at least ;0))

#### Saxdude

#6
##### Sep 22, 2009, 02:11 pm
Quote
i hate college physics,,, it was so hard...
that problem of yours,,, i solved it 7 years
ago,,, now i forgot how... <snip>

Dude, it looks like your keyboard is broken. The caps don't work, and some keys are stuck.

#### TBAr

#7
##### Sep 23, 2009, 02:52 pmLast Edit: Sep 23, 2009, 03:03 pm by TBAr Reason: 1
Um, it was spam. Got you to notice it, though.

Quote

Cielo Drea Bonita
Posts: 2
Date Registered: 15.Sep.2009 at 03:39:08 [* varies depending on your time zone]
Last Online: 15.Sep.2009 at 04:52:33
Last Post: 15.Sep.2009 at 04:50:55
_____________________
dressupgames | bratz games | dress up games | dress up

#### mowcius

#8
##### Sep 23, 2009, 08:27 pm
It may be spam-ish but it was a human who typed it...

#### TBAr

#9
##### Sep 24, 2009, 03:02 amLast Edit: Sep 24, 2009, 03:05 am by TBAr Reason: 1
Agreed. It took over an hour for them to find a post on this board with words they could understand though.

#10
:dunce:

Go Up