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

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The discussion revolves around using the formula V^2 = u^2 + 2*a*d to find acceleration in a scenario involving a racing driver who decelerated from 173 km/h to 0 km/h over a distance of 66 cm. The user seeks clarification on the variables in the formula, identifying v as final velocity, u as initial velocity, a as acceleration, and d as distance. Given the known values of mass (55 kg), initial velocity (173 km/h), final velocity (0 km/h), and stopping distance (66 cm), the main challenge is rearranging the formula to solve for acceleration. The user expresses uncertainty about how to proceed with the calculations. Understanding the formula and correctly substituting the values is crucial for finding the unknown acceleration.
zachattak
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Homework Statement



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

Homework 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 I am having trouble finding the Fnet.

The Attempt at a Solution



honestly, i don't know where to start.
 
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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?
 
CompuChip said:
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?
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 that's all he gave us
v=final velocity
u=initial velocity
a=acceleration
d=distance


sorry about this, this is my first post on here and yeah, sorry mate.
 
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?
 
yeah, my main problem is i don't know how to rearrange the formula =S
 
OK, what formula do you get when you plug in all the given values?
 
The book claims the answer is that all the magnitudes are the same because "the gravitational force on the penguin is the same". I'm having trouble understanding this. I thought the buoyant force was equal to the weight of the fluid displaced. Weight depends on mass which depends on density. Therefore, due to the differing densities the buoyant force will be different in each case? Is this incorrect?

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