Question
A technician at the top of a 200m tall radio tower drops her hammer.
how much time does it take for the hammer to strike the ground?
how much time does it take for the hammer to strike the ground?
Answers
Damon
ke at bottom = (1/2) m v^2 = m g h
so v at bottom = sqrt (2 g h)
so average v = max v/2 = (1/2) sqrt(2 gh)
average v = .5 sqrt(2*9.81*200)
= 31.3 m/s
time = distance /speed
= 200 /average v = 200/31.3 = 6.39 seconds
so v at bottom = sqrt (2 g h)
so average v = max v/2 = (1/2) sqrt(2 gh)
average v = .5 sqrt(2*9.81*200)
= 31.3 m/s
time = distance /speed
= 200 /average v = 200/31.3 = 6.39 seconds
Elena
h=gt²/2
t=sqrt(2h/g) =sqrt(2•200/9.8)=6.39 s
t=sqrt(2h/g) =sqrt(2•200/9.8)=6.39 s