Problema Solution
Choi can walk 123 m in 56 seconds. Standing on a moving sidewalk at an​ airport, she can travel 123 m in 40 seconds. How long will it take her to travel 123 m if she walks on the moving​ sidewalk?
Answer provided by our tutors
Walking speed on a normal sidewalk: v1 = 123/56 m/s
Moving speed when standing on the moving sidewalk: v2 = 123/40 m/s
Walking speed going the same way on the moving sidewalk: v1 + v2 = 123/56 + 123/40 = 369/70 m/s
d = 123 m
t = time of the travel when walking on the moving side walk
Since speed = distance/time follows time = distance/speed:
t = d/(v1 + v2)
t = 123/(369/70)
t = 70/3
t = 23 1/3 s
t = 23.3 seconds
Choi will travel the 123 meters by walking on the moving sidewalk is 23.3 seconds.