Basic Formula: 
A = VfVi
/ t 
A = Acceleration 
Vf
= Final Velocity 
Vi = Initial
Velocity 
t = time 



Units: 
Velocity will always be a
distance unit over a time unit. (mi/hr) (m/sec) (km/hr) 

Acceleration will always be a velocity (m/s,
mi/hr) over a time (sec). Examples would be: m/s/s or m/s^{2} 

Time units: min (minute), sec
(second), hr (hours) 
These problems are not really
very hard to solve as long as you match the given numbers (usually using
their units) with the formula above. You can also use the triangle
method. The triangle is an easy way to figure out how to manipulate
the formula. In order to use it, look at the triangle. Put
your finger over the variable or letter you need to solve for. For
example, if you are looking for the acceleration, you will cover up the
letter A. Now you do the mathematical function it shows. If
the letters are beside each other, you multiply. This formula is bit
more complicated just because it has the Vf and Vi.
These are not all that bad. The Vf is the final
velocity of the object. The Vi is the starting
velocity. We have to know both since acceleration is a average
change. If one is on top of the other, you divide. If you
would like to check out some sample problems, click on this link:
<acceleration sample problems> 
The triangle: 
You can see that if you were trying to solve for
acceleration. Then the (VfVi)
would be over the T, so you would divide the
change in velocity that happened by the time it took. Similarly, if
you wanted to solve for the time it took, then the change in velocity
would be divided by the acceleration since the change in velocity is on
the top. If you wanted to solve for change in velocity, then the
acceleration would be located beside the time, so you would multiply them
together. NOTE: If your object is slowing down, the the Vf 
the Vi will give you a negative number. When you divide that by the
positive time, you will get a negative number. THAT IS
CORRECT! Slowing down gives a negative acceleration. Speeding
up gives a positive one. :)

