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A body dropped from top of a tower covers a distance 7x in last second of its journey where x is distance covrd in first second.?
Find time taken to reach the ground...??
1 Answer
- denisLv 46 years agoFavorite Answer
After first second:
v = vo + gt
v = 0 -9.8(1)
v = -9.8m/s
v^2 = vo^2 + 2gΔy
(-9.8)^2 = 0 + 2(-9.8)Δy
96.04 = -19.6Δy
Δy = -4 9m in the first second.
After the final second, the body drops 7(-4.9) = -34.3m and its displacement is given by
Δy = vot + 1/2gt^2
0 - 34.3 = vo(1) + 1/2(-9.8)(1)^2
-34.3 = vo - 4.9
vo = -29.4m/s
We can now find the displacement between the final velocity after first second and initial velocity before final second:
v = vo + gt
-29.4 = -9.8 - 9.8t
-19.6 = -9.8t
t = 2s
So the total time is T = 1 + 2 + 1 = 4s