Question

a marathon runner starts her race at a speed of 3 m/s. by the end of the race, 5 hours later, her speed is 2.8 m/s. what was her average acceleration?

Answer 1

Answer: Acceleration, a= -1.11*10^-5

Step-by-step explanation:

Using a= (V(final speed)- U(Initial speed) )/ TIME IN SECONDS

5hr to seconds is 5*60*60=18,000s

(2.8m/s-3m/s)/ 18,000s = -1.11*10^-5

I'm sorry I wasn't able to explain well, but I hope this helps.