To qualify to run in the 2005 boston marathon, a distance of 26.2 miles, an 18-year-old woman had to have completed another marathon in 3 hours and 40 minutes or less. a) to qualify, what must a woman's average speed have been in miles per hour? b) to qualify, what must a woman's average speed have been in meters per second? there are 1609 m in a mile.

7,14545 mph and 3,1936 m/s

Explanation:

The average speed is calculated by dividing the displacement over time, then it is 26,2 miles/(3 2/3 hours), here 3 (2/3) hours is a mixed number, that represents 11/3 hours or 3,66 hours. Then the average speed is 7,14545 mph, now to turn this into meters per second, we notice as mentioned that 1 mile =1609 meters and 1 hour=3600 seconds. Then 7,14545 miles/hour* (1 hour/3600 seconds) * (1609 meters/1 mile)=3,1936 m/s

the answer is b ) square root of 5

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