At 7 a.m., Barbara and Julie raced off together from the starting point of a route. Barbara ran at an average speed of 2 m/s. Julie ran at an average speed of 3 m/s. Upon reaching the end of the route, Julie rested for 6 minutes. She then immediately ran back along the same route at 3 m/s. At 7.25 a.m., Barbara met Julie.
- 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 7 a.m. to 7.25 a.m. = 25 min
Duration that Barbara ran = 25 min
Duration that Julie ran = 25 - 6 = 19 min
1 min = 60 s
19 min = 19 x 60 = 1140 s
25 min = 25 x 60 = 1500 s
Distance that Barbara ran
= 2 x 1500
= 3000 m
Distance that Julie ran
= 3 x 1140
= 3420 m
Distance that Barbara and Julie ran
= 3000 + 3420
= 6420 m
1000 m = 1 km
6420 m = 6420 ÷ 1000 = 6.42 km
(b)
Length of the trail
= 6.42 ÷ 2
= 3.21 km
Answer(s): (a) 6.42 km; (b) 3.21 km