Wednesday, May 7, 2025

SIN Bin: 82

By Department Faculty

Problem

According to the Goodness book of Records, someone climbed the Empire State Building (1570 steps high at 24cm/step) in 12.5 minutes. According to the basic laws of physics, about how long would the trip back down take? Assume that he steps off the top with no initial vertical velocity and falls freely to the bottom with negligible air resistance. Provide your answer in seconds. 

  1. 6.1 
  2. 8.7 
  3. 14 
  4. 31 
  5. 75 

Solution SIN Bin: 82

B. 8.7

Answer Explanation: What goes up must come down! The height is H = 1570 X 0.24m. The time for free fall from rest is t = √(2H/g). Plug it in and find answer B.