At 9 a.m., Lynn and Kimberly raced off together from the starting point of a route. Lynn ran at an average speed of 2 m/s. Kimberly ran at an average speed of 3 m/s. Upon reaching the end of the route, Kimberly rested for 4 minutes. She then immediately ran back along the same route at 3 m/s. At 9.50 a.m., Lynn met Kimberly.
- Find the total distance covered by the two runners when they met each other. Express your answer in km.
- Find the length of the trail in km.
(a)
From 9 a.m. to 9.50 a.m. = 50 min
Duration that Lynn ran = 50 min
Duration that Kimberly ran = 50 - 4 = 46 min
1 min = 60 s
46 min = 46 x 60 = 2760 s
50 min = 50 x 60 = 3000 s
Distance that Lynn ran
= 2 x 3000
= 6000 m
Distance that Kimberly ran
= 3 x 2760
= 8280 m
Distance that Lynn and Kimberly ran
= 6000 + 8280
= 14280 m
1000 m = 1 km
14280 m = 14280 ÷ 1000 = 14.28 km
(b)
Length of the trail
= 14.28 ÷ 2
= 7.14 km
Answer(s): (a) 14.28 km; (b) 7.14 km