At 9 a.m., Kimberly and Tammy raced off together from the starting point of a course. Kimberly ran at an average speed of 1 m/s. Tammy ran at an average speed of 3 m/s. Upon reaching the end of the course, Tammy rested for 4 minutes. She then immediately ran back along the same route at 3 m/s. At 9.50 a.m., Kimberly met Tammy.
- 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 Kimberly ran = 50 min
Duration that Tammy 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 Kimberly ran
= 1 x 3000
= 3000 m
Distance that Tammy ran
= 3 x 2760
= 8280 m
Distance that Kimberly and Tammy ran
= 3000 + 8280
= 11280 m
1000 m = 1 km
11280 m = 11280 ÷ 1000 = 11.28 km
(b)
Length of the trail
= 11.28 ÷ 2
= 5.64 km
Answer(s): (a) 11.28 km; (b) 5.64 km