posted by Elizabeth on .
Janet jumps oﬀ a high diving platform with
a horizontal velocity of 2.37 m/s and lands in
the water 1.9 s later.
How high is the platform? The acceleration
of gravity is 9.8 m/s
Answer in units of m
The horizontal velocity is unimportant. No one is asking how far away from the platform she lands.
So, all we want to know is how far one falls in 1.9s under gravity.
s = .5at^2 = 4.9*1.9^2 = 17.7m
That's a nice high platform!