Question

From the top of a tower, $80\, m$ high from the ground, a stone is thrown in the horizontal direction with a velocity of $8\, ms^{-1}.$ The stone reaches the ground after a time ?t? and falls at a distance of ?d? from the foot of the tower. Assuming $g=10\, ms^{-2},$ the time t and distance d are given respectively by

• A. 6 s, 64 m
• B. 6 s, 48 m
• C. 4 s, 32 m
• D. 4s, 16 m

Answer 1

Answer: (C)

4 s, 32 m

Answer 2

Given, $h=80\, m ,\, v=8\, ms ^{-1}$ and $g=10\, ms ^{-2}$
Here,
$h =\frac{1}{2} g t^{2}$
$80 =\frac{1}{2} \times 10 \times t^{2}$
$t =4\, s$
and $x =v t=8 \times 4=32\, m$