A high-performance sports car can go from 0 to 100 mph in 6.6 s. (Assume the car travels in the positive direction. Indicate the direction with sign of you answer.)
a) What is the car's average acceleration (in SI units; meter-kilogram-second)?
b) The same car can come to a complete stop from 27m/s in 4.1s ; What is its average acceleration?