The parachute on a race car of weight 8840 N opens at the end of a quarter-mile run when the car is traveling at 35 m/s. What total retarding force must be supplied by the parachute to stop the car in a distance of 1100 m?

Use the equation: v^2 = u^2 + 2as

v is the final velocity of the car, here 0
u is the initial velocity of the car, here 35
a is the acceleration you're looking for and should be negative,
s is the displacement of the car, here 1100.

Solve for a :)

Can you post what you get?