How do I Calculate Acceleration from Distance and Time?

[hogga10]

Homework Statement

Running an experiment at school, and am now up to the discussion and data analysis.
I have to work out an objects acceleration in m/s^-2 over 80cm.
all i have is the distance (80cm) and the time (1.69 seconds)
i do not know how to do this without final velocity.

Homework Equations

a=v-v₀/t this is what i would generally use.
s=v₀*t+1/2a*t² is this what i need? and if so, how do i use it?

The Attempt at a Solution

i have a feeling that it is fairly simple, but I've been working on this too long and my brain has turned to mush :S

other than thinking of those formulas. i don't know where to start.

 

[rock.freak667]

s=v₀*t+1/2a*t² is this what i need? and if so, how do i use it?

yes this equation you will need.

I assume the person started off at rest when you started timing, if so then v₀ = 0.

You know s and t, so rearrange to get 'a'.

 

[hogga10]

how can i rearrange this? I am not sure as i have missed a lot of lessons due to being ill :(

 

[rock.freak667]

how can i rearrange this? I am not sure as i have missed a lot of lessons due to being ill :(

Your equatio is reduced to

s = (1/2)at²

so multiply by 2

then divide by t².

 

[hogga10]

thank you for your help

 

[Borek]

how can i rearrange this? I am not sure as i have missed a lot of lessons due to being ill :(

Rearranging has nothing to do with physics, it is a pure algebra skill. If you have troubles here, you should brush up your math as you will be completely lost in physics sooner than you think.

 

[Rayquesto]

physics is highly conceptual and requires a heavy math talent (or you can get good at it by spending a huge amount of time), but rearranging skills will helps a whole lot in a physics class. I'd say the physics mind should be one that can approach a problem with imagination, than with memorization, but it's hard to imagine without remembering some stuff. But out of all the advice given to me over time, I have to say that the worst one is that you must be a complete expert at algebra before taking a physics class. I'm alright at physics, but my math is in some way or another just horrible. If you want to take physics and do better, I'd say that an expansion to imagination skills is the key, but not necessarily MATH! I think I got better at math taking physics, because I could apply my imagination to the problems and all the "pointless" math you do in algebra 1, 2, precal, and some calculus all seems to make sense, seems to apply, and seems to have a point.

 

[hogga10]

Thankyou all for your help. I am feeling much better after a sleep and I've done all of the necessary equations for the report. thanks again