At 9 a.m., Opal and Min raced off together from the starting point of a track. Opal ran at an average speed of 1 m/s. Min ran at an average speed of 3 m/s. Upon reaching the end of the track, Min rested for 3 minutes. She then immediately ran back along the same route at 3 m/s. At 9.45 a.m., Opal met Min.
- 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 9.45 a.m. = 45 min
Duration that Opal ran = 45 min
Duration that Min ran = 45 - 3 = 42 min
1 min = 60 s
42 min = 42 x 60 = 2520 s
45 min = 45 x 60 = 2700 s
Distance that Opal ran
= 1 x 2700
= 2700 m
Distance that Min ran
= 3 x 2520
= 7560 m
Distance that Opal and Min ran
= 2700 + 7560
= 10260 m
1000 m = 1 km
10260 m = 10260 ÷ 1000 = 10.26 km
(b)
Length of the trail
= 10.26 ÷ 2
= 5.13 km
Answer(s): (a) 10.26 km; (b) 5.13 km