Question

A body travels half of its total path in the last second of its free fall. What is the duration of its free fall?

Answer 1

S = ut+½at²

u = 0 ( freefall )

Let total time be ‘t’

Total distance be ‘S’

So,

S/2 = ½(9.8)(T-1)² -[1]

S = ½(9.8)(T)² -[2]

From [1] & [2]

2{½(9.8)(T-1)²} = ½(9.8)(T)²

2(T-1)² = (T)²

√2(T-1) = T

T= √2/(√2–1)

T = 3.4142 second.