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प्रश्न
How long will a stone take to fall to the ground from the top of a building 80 m high
उत्तर
Height, s = 80m
g = 10 m/s2
Using the second equation of motion,
S = ut + (1/2) gt2
Or, 80 = 0+ (1/2) (10) (t) 2
Or, (t) 2 = 16
Or, t = 4s
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