Homework Help: Very likely a stupid question =S Finding acceleration with formula V^2=u^2+2*a*d

1. Jun 2, 2010

zachattak

1. The problem statement, all variables and given/known data

racing driver, David Purley, survived a deceleration from 173km/h to 0km/h in a distance of 66cm in a crash. body mass = 55kg
2. Relevant equations

V^2=u^2+2*a*d is what i have to work with at the moment, i was thinking of using a=Fnet/mass. but im having trouble finding the Fnet.

3. The attempt at a solution

honestly, i dont know where to start.

2. Jun 2, 2010

CompuChip

In the formula you gave,
$$v^2 = u^2 + 2ad$$
what do all the letters mean?
I.e. what does v stand for, and u, and a and d?
Can you also list for which ones values are given in the problem and which ones are still unknown?

3. Jun 2, 2010

zachattak

um, the only variables and values they gave me are, the mass of the driver '55kg', the initial velocity '173 km/h' final velocity '0km/h' and the stopping distance '66cm'
i understand that there are a few other things which may help, but thats all he gave us
v=final velocity
u=initial velocity
a=acceleration
d=distance

4. Jun 2, 2010

CompuChip

Look closely at the two lists.
Seems to me that the formula is very useful... there is just one unknown quantity in there, isn't it?

5. Jun 5, 2010

zachattak

yeah, my main problem is i dont know how to rearrange the formula =S

6. Jun 5, 2010

CompuChip

OK, what formula do you get when you plug in all the given values?