Question

A passenger is walking on an escalator at a speed OGN 6km/hr relative to the he escalator. He starts from point p on the ground and reaches a point q. The escalator Ian moving at 3km/hr relative to the ground in the direction of q. If pq is 120m, find the time take some to reach q.?

Answer 1

Since the passenger is walking on a moving walkalator we have to consider the concept of relative motion. Since the passenger and the walkalator are moving in the same direction, the relative speed will be the sum of the speeds of the passenger and the walkalator.  

Speed of passenger wrt ground = (speed of passenger wrt walkalator) + (speed of walkalator)  

= 6+3 = 9 km/hr  

Converting the speed into m/s we get 9 x 5/18 =2.5 m/s  

Hence, time taken to cover 120m = 120/2.5 = 48s

Answer 2

Given: A passenger is walking on an escalator at a speed OGN 6km/hr relative to the he escalator. He starts from point p on the ground and reaches a point q. The escalator Ian moving at 3km/hr relative to the ground in the direction of q.

To find: If pq is 120m, the time take taken to reach q.

Solution: If pq is 120 m, the time take taken to reach q is 13.33 hours.

Speed, time and distance are related to one another as shown in the formula written below.

$s = \frac{d}{t}$

Here, s is the speed of the passenger, d is the distance between p and q and t is the time taken by him. Now, the relative speed of the passenger with respect to the elevator and the speed of the elevator with respect to the ground is given. So, the speed of the passenger with respect to the ground can be written as

$6 + 3 = 9 km/hr$

Also, the distance between p and q is 120 m. Hence, the time taken can be calculated as

$9 = \frac{120}{t}$

$t = 13.33 hours$

  $= 48000 s$

Therefore, if pq is 120 m, the time take taken to reach q is 13.33 hours.