a driver traveling at 50 mph sees a wall at a certain distance ahead. the driver applies a brakes immediately (perception time is 3 second)

If the driver has a perception time of 3 seconds, it means that it takes them 3 seconds to realize that there is a wall ahead and react by applying the brakes.

Assuming that the driver applies the brakes immediately after perceiving the wall, we can calculate the distance traveled during the perception time.

Distance traveled during perception time:
= Speed x Time
= 50 mph x (3 seconds x 1 hour/3600 seconds)
= 50 mph x (3/3600) hour
= 0.04 miles

Therefore, during the 3 seconds of perception time, the driver will travel approximately 0.04 miles.

Please note that this calculation only considers the perception time and does not account for any additional reaction time or braking distance.