Time taken by an object falling from rest to cover the height of h1 and h2 is respectively t1 and t2. Then the ratio of t1 to t2 is:
A
h1:h2
B
h1:h2
C
h1:2h2
D
2h1:h2
Step-by-Step Solution
Equation of Motion: For an object falling freely from rest (u=0) under gravity (a=g), the distance covered h in time t is given by the second equation of motion:
h=ut+21gt2h=0+21gt2⟹h=21gt2
Relation between Time and Height: Rearranging the equation for time:
t=g2h
Since g is constant, t∝h.
Calculate Ratio:
For height h1, time t1=g2h1
For height h2, time t2=g2h2
Ratio t2t1=2h2/g2h1/g=h2h1 .
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