# Physics still don't get it

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Given: g=9.81 m/s square.
The parachute on a race car that weighs 8042 N opens at the end of a quarter-mile run when the car is traveling 35 m/s. What net retarding force must be supplied by the parachute to stop the car in a distance of 1020 m? Answer in units of N.

• Physics still don't get it -

m = weight in Newtons/ 9.81

Change in kinetic energy = average force * distance.
The change in KE is all the KE, since it stopped.

(1/2) m v^2 at the start = F * 1020

So F = (1/2) m v^2 / 1020

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