Its physics. I got an answer but I'm not sure if I'm right

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Originally Posted by Prostaff

Its physics. I got an answer but I'm not sure if I'm right

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Your question got cut off - what are you trying to calculate, the car's rate of deceleration? Also - please tell us what answer you got and how you arrived at it, and we can tell you whether it's correct or not.

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Originally Posted by ebaines

Your question got cut off - what are you trying to calculate, the car's rate of deceleration? Also - please tell us what answer you got and how you arrived at it, and we can tell you whether it's correct or not.

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Yeah, I'm trying to find the car's rate of deceleration. I got
Time=2.5
Velocity due to gravity=10m/s
So deceleration=-(0-10/2.5)=4m/s^2

To find the acceleration of the car use F=ma: F is the force applied by the brakes in the direction opposite of travel (hence is a negative number), and m is the mass of the car. So from F=ma you can rearrange to get: a = F/m = -400N/1000Kg.

Why diid you include 'g' (acceleration due to gravity? For a car on a level road (which I assume this is) gravity acts perpendicular to the direction of motion and hence has no effect on the car's acceleration.

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Originally Posted by ebaines

To find the acceleeation of the car use F=ma: F is the force applied by the brakes in the direction opposite of travel (hence is a negative number), and m is the mass of the car. So from F=ma you can rearrarnge to get: a = F/m = -400N/1000Kg.

Why diid you include 'g' (acceleration due to gravity? For a car on a level road (which I assume this is) gravity acts perpendicular to the direction of motion and hence has no effect on the car's acceleration.

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Thanks for the reply. I understand it now, it was on my test and I obviously screwed it up. Thanks though