Basic Kinematic Equations

1. Sep 9, 2010

Siege

I already typed a long drawn out post, so I am going to simplfy it.

I am having trouble using algebra to rearrange equation.

For Example,

v=d/t
And so, to solve for both t and d, I do the following

vt=d/t x t
vt=d
vt/v=d/v
t=d/v

I have difficulty with most if not all the other equations. For example, the formula for acceleration.

a=Vf-Vi/t
Solve for t

a=Vf-Vi/t
at=Vf-Vi/t x t
at + Vi=Vf -Vi + Vi
at+Vi=Vf
Vf-Vi/a=t

This is my attempt at it. I multiplied by t, then eliminated the negative, and finally divided by a.

2. Sep 9, 2010

rock.freak667

Yes those are correct.

For the second one, you could have done it simpler instead of expanding out:

a=(vf-vi)t

multiplying both sides by 't'

at=(vf-vi)

divide both sides by 'a'

t=(vf-vi)/a

3. Sep 10, 2010

Siege

Thank you very much.

Are there any tricks to rearranging equations? or rules to follow?