A stone that starts at rest is in free fall for 4.0 seconds. What's the stone’s velocity after 4.0 seconds?
and stone’s displacement during this time?
Physics
and stone’s displacement during this time?
Physics
oldschool
Vf = Vi + a*t = 0 + 9.8*4 = 39m/s
d = do + Vo*t +½*a*t² = 0 + 0*t +½*9.8*4² = 78.4 or 78m with 2 s.f.
Morningfox
Each second, the stone gains speed of 9.8 m/s, downwards.
oubaas
final velocity V = g*t = -9.806*4 = -39.2 m/sec
displacement d = V*t/2 = g*4*4/2 = g*8 = -9.806*8 = -78.4 m/sec
displacement d = g/2*t^2 = g*16/2 = g*8 = -9,806*8 = -78.4 m
displacement d = V^2/2g = g^2*16/2g = g*8 = -9.806*8 = -78.4 m