Posted by philip on Friday, September 23, 2011 at 12:01pm.
Just dust off your good old formulas:
v = at
s = 1/2 at^2
First, get better units:
20 km/hr * 1000m/km * hr/3600sec = 5.555m/s
Velocity changed from 0 to 5.555m/s in 21s.
v = at
5.555 = 21a
a = 0.265m/s^2
s = .5at^2 = .5*0.265*21^2 = 58.43m
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