Word Problem

Question

A skyscraper is 485485 m tall. Its elevators rise at 56.8856.88 km/hr. How many seconds would it take for an elevator to rise the entire height of the building, nonstop?

Answer 1

OK, notice that you have a mix of units: meters, kilometers, hours and seconds.  You want your answer in seconds, not hours so we need to convert the rate (speed) of the elevator from km/hr to m/s:

 

(56.88 km/hr)(1000 m/km)(1/3600 hr/sec) = ________  m/s

 

To find the time, divide the height of the building (485 m) by the elevator rate (speed) in m/s that you compute above.

 

distance = rate*time

distance/rate = time