a 10k race was held the first place finisher completed the 10km run in 29.5 minutes what was the average speed in miles per hour. In another race the person is given a head start and if they beat the first place finisher at the end the win $2,500 the chosen winner was given a 2.1 head start at what minimum average speed in miles per hour did he have run in order to win?

Question

a 10k race was held the first place finisher completed the 10km run in 29.5 minutes what was the average speed in miles per hour. In another race the person is given a head start and if they beat the first place finisher at the end the win $2,500 the chosen winner was given a 2.1 head start at what minimum average speed in miles per hour did he have  run in order to win?

Henry · Answer

Speed = 10km/29.5min * 1mi/1.6km * 60min/h = 12.71 mi/h.

Henry · Answer

d1 = 10km/1.6 = 6.25 mi. d1 = r1*t1 = 12.71*t1 = 6.25, t1 = 0.492 h. d2 = (10-2.1)km/1.6 = 4.94 mi. d2 = r2*t1 = r2*0.492 = 4.94, r2 = 10 mi/h. = min. speed to win.