A person walks up a stalled 20 m long escalator in 79 s. When standing on the same escalator, now moving, the person is carried up in 60 s. How much time would it take that person to walk up the moving escalator?
ratewalking= 20/79 ratemoving=20/60
time= distance/added rates
so add the rates, and divide into distance.
To find out how much time it would take for the person to walk up the moving escalator, we need to calculate the combined rate of the person's walking speed and the speed of the escalator.
The rate of the person walking up the stationary escalator can be calculated as distance divided by time:
rate_walking = 20 m / 79 s
The rate of the person being carried up the moving escalator can be calculated as distance divided by time:
rate_moving = 20 m / 60 s
To find the combined rate, we need to add the rate of walking with the rate of the escalator.
Combined rate = rate_walking + rate_moving
Next, we can calculate the time it would take for the person to walk up the moving escalator using the combined rate.
time = distance / combined rate
Now, let's substitute the values into the formula:
combined rate = (20 m / 79 s) + (20 m / 60 s)
time = 20 m / ( (20 m / 79 s) + (20 m / 60 s) )
By simplifying the expression, you can find the answer.