An object is dropped off a building measuring 65m tall. How long does it take for the object to fall?

1 Answer
Feb 27, 2018

It will take approximately #3.6 \ "s"#.

Explanation:

We use the equation:

#d=1/2g\t^2#

where #t# is the time in seconds.

Arranging for #t#, we get

#t=sqrt((2d)/g)#

So, we plug in values into the equation, and get

#t=sqrt((2*65 \ "m")/(9.81 \ "m/s"^2)#

#t=sqrt((130color(red)cancelcolor(black)"m")/(9.81color(red)cancelcolor(black)"m""/s"^2)#

#t=sqrt(13.2517839 \ "s"^2)#

#t=3.64 \ "s"~~3.6 \ "s"#

So, it takes approximately #3.6 \ "s"# for the object to fall.

Source:

https://en.wikipedia.org/wiki/Equations_for_a_falling_body