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2Pac
Oct17-04, 08:56 PM
Hey if anyone could please tell me how to do this it would be a great help.

ok the question asks about an accelerating car. The mass of the car is 1200kg. When the engine is floored it creates a constant forward force of 9600N. The drag created by the car is equal to this equation: D=160v. Determine the velocity of the car after it has been floored for 8 seconds.

Tide
Oct17-04, 09:14 PM
You just need to solve the equation of motion:

m\frac {dv}{dt} = 9600 - 160 v

Just remember to keep your units consistent!

2Pac
Oct17-04, 09:18 PM
actually i am not familiar with that equation. and my calculus is poor. So if anyone could explain this further, thanks!

HallsofIvy
Oct18-04, 07:13 AM
1200\frac {dv}{dt} = 9600 - 160 v= 160(60- v)
is the same as
\frac{dv}{60-v}= \frac{160}{1200}dt= \frac{1}{20}dt

To integrate the left side, let u= 60- v so that du= -dv and the equation becomes
-\frac{du}{u}= \frac{1}{20}dt

You ought to be able to integrate that.