Question

A firefighter jumps out of the window into a net ,if the window is 25m above the net,at what speed does the firefighter hit the net?and how long will it take the firefighter to hit the net?

Answer 1

G = 9.8 m/s^2.

the formula to calculate distance is:

\[Dist = (1/2) G t^2\]

(see: http://en.wikipedia.org/wiki/Equations_for_a_falling_body)

So substituting we get
\[25 = (1/2) 9.8 t^2\]
\[t^2 = 50/9.8\]
\[t = \sqrt{50/9.8}\]
\[t = 5\sqrt{2}/\sqrt{9.8}\]