Question

Lance arrives at the airport (with flowers and balloons in hand) to welcome a friend. Her plane is delayed. While waiting, he notices that it takes 2 minutes 47 seconds to get down the hall on the moving sidewalk. while walking (not on the moving sidewalk) it took him 112 seconds. If he walks while on the sidewalk, how long (s) will it take him?

Answer 1

Answer:

    t = 67.04 s

Explanation:

given,

time taken by Lace on the side walk = 2 min 47 s

                                                             = 167 s

time taken by the Lace while walking = 112 s.

now, time taken by the Lace when he is walking on the side walk = ?

Assume the distance be equal to 'd'

speed of Lace on side walk

we know, distance = speed x time

     $v_{sidewalk}=\dfrac{d}{167}$

speed of the lace while walking

     $v_{walking}=\dfrac{d}{112}$

time taken by Lace to cover the distance by walking on the side walk

  $t = \dfrac{distance}{v_{sidewalk}+v_{walking}}$

   $t = \dfrac{d}{\dfrac{d}{167}+\dfrac{d}{112}}$

   $t = \dfrac{167\times 112}{167+112}$

        t = 67.04 s

time taken by the Lace walking on the side walk is equal to 67.04 s