Calculating Acceleration for a Sports Car Stopping from 90 km/h in 50 m

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To calculate the acceleration of a sports car stopping from 90 km/h over a distance of 50 m, the equation v² = v0² + 2a(x-x0) is used. The initial speed is converted to approximately 25 m/s, leading to a calculation of 6.25 m/s² for acceleration. However, there is confusion regarding the sign of the acceleration, as it should be negative due to deceleration. Verifying the result by substituting back into the equation can confirm its accuracy, ensuring the final velocity reaches zero. The discussion emphasizes the importance of checking calculations and understanding the physical context of acceleration.
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[SOLVED] What am I missing here?

Homework Statement



A sports car is advertised to be able to stop in a distance of 50 m from a speed of 90 km/h. What is its acceleration in m/s²?


Homework Equations



v² = v0² + 2a(x-x0)

The Attempt at a Solution



I attempted to solve for a using this equation, but came out with a value like 6 m/s² which I don't believe is correct. The first thing I did was multiply 90 km/h by .2777777 to convert it to m/s which gave me roughly 25 m/s. I plugged in 625 in for v0² (25²) and divided that by 50 m (50 - 0). I got 12.5 which after divided by 2 gave me 6.25, which like I said above I can't imagine is correct. Help :(
 
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You seem to have done everything perfectly, except perhaps the sign of the acceleration. Why do you not think think its correct?
 
I don't know I'm just really bad at this stuff. Thanks for the clarification anyway.
 
A very simple way to check is to just put the value back into the equation and see if it does what you expect. In this case you would expect the final velocity to be 0. Or in other words, both terms on the right hand side would have to be equal.
 
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