Question

A body thrown vertically upward with an initial velocity $u$ reaches maximum height in 6 second. The ratio of the distances travelled by the body in the first second and seventh second is

• A. 1 : 1
• B. 11 : 1
• C. 1 : 2
• D. 1 : 11

Answer 1

Answer: (B)

Time of ascent $=\frac{u}{g}=6\,s$
$\Rightarrow u=60\,m / s$
Distance in first second,
$h_{\text {first }}=60-\frac{g}{2}(2 \times 1-1)=55\, m$
Distance in seventh second will be equal to the distance in first second of vertical downward motion.
$h_{\text {seventh }} =\frac{g}{2}(2 \times 1-1)=5\, m $
$\Rightarrow h_{\text {first }} / h_{\text {seventh }} =11: 1$