3. A car has an acceleration of +2m/s2. What does this tell you about the velocity of the car? What is meant by an acceleration of -2m/s2?​

acceleration is the rate of change of velocity

therefore in the above statement, the velocity increases twice per second.

when acceleration is negative, then it is accelerated motion.

ie. the car accelerates twice per second

the duration of a photographic flash is related to an rc time constant, which is 0.100 μs for a certain camera.