Question

a passenger elevator in the sears tower in chicago can lift people 960 feet in 1 minute and 30 seconds. How fast must the freight elevator be traveling if it lifts cargo the same height but in 2 minutes and 30 seconds

Answer 1

Given that a passenger elevator in the sears tower in Chicago can lift people 960 feet in 1 minute and 30 seconds (1.5 minutes). This means that the lift is travelling with a speed of:

$speed= \frac{distance}{time} = \frac{960}{1.5} =640ft/min$

If the elevator lifts cargo through the same height in 2 minutes and 30 seconds (2.5 minutes), then the speed is given by:

$speed= \frac{960}{2.5} =384ft/min$