Answer:
20 seconds
Step-by-step explanation:
s = Distance traveled by elevator = 300 ft
t = Time taken = 5 seconds
Velocity is given by
[tex]v=\dfrac{s}{t}\\\Rightarrow v=\dfrac{300}{5}\\\Rightarrow v=60\ \text{ft/s}[/tex]
Distance to the observation level from the lobby = 1200 ft
Time taken is given by
[tex]t=\dfrac{1200}{60}\\\Rightarrow t=20\ \text{s}[/tex]
Time taken to reach the observation level from the lobby is 20 s.