Answer:
He will take 60 seconds to move from one end of the sidewalk to other.
Step-by-step explanation:
Given:
A person on a moving sidewalk,
21 feet in 7 seconds
Then 180 feet
To Find:
Total time =?
Solution:
Speed:
Speed is defined as the rate of distance covered in per unit time.
It is given as
[tex]\textrm{Speed }=\dfrac{\textrm{Distance}}{Time}[/tex]
Substituting the given values we get
[tex]\textrm{Speed }=\dfrac{21}{7}=3\ m/s[/tex]
Now, With this speed if he walk 180 feet then the time is
[tex]\textrm{Time}=\dfrac{\textrm{Distance}}{Speed}[/tex]
Substituting Speed and Distance we get
[tex]\textrm{Time}=\dfrac{180}{3}=60\\\\Time=60\ s[/tex]
He will take 60 seconds to move from one end of the sidewalk to other.