At 8 a.m., Eva and Opal raced off together from the starting point of a track. Eva ran at an average speed of 2 m/s. Opal ran at an average speed of 4 m/s. Upon reaching the end of the track, Opal rested for 4 minutes. She then immediately ran back along the same route at 4 m/s. At 8.30 a.m., Eva met Opal.
- 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 8 a.m. to 8.30 a.m. = 30 min
Duration that Eva ran = 30 min
Duration that Opal ran = 30 - 4 = 26 min
1 min = 60 s
26 min = 26 x 60 = 1560 s
30 min = 30 x 60 = 1800 s
Distance that Eva ran
= 2 x 1800
= 3600 m
Distance that Opal ran
= 4 x 1560
= 6240 m
Distance that Eva and Opal ran
= 3600 + 6240
= 9840 m
1000 m = 1 km
9840 m = 9840 ÷ 1000 = 9.84 km
(b)
Length of the trail
= 9.84 ÷ 2
= 4.92 km
Answer(s): (a) 9.84 km; (b) 4.92 km