Question

A stone is dropped from a cliff. What will be its speed when it has fallen 100 m? (g = 9.8 m/s2)
(a) √2000 m/s
(b) √1960 m/s
(c) √200 m/s
(d) √196 m/s
please give appropiate answer according to the option and question i request you .

Answer 1

kinematics equation

\begin{gathered} {v}^{2} = {u }^{2} + 2as \\ {v}^{2} = 0 + 2 \times 9.8 \times 100 \\ v = \sqrt{1960} \\ v = 14 \sqrt{10} m \: per \: s\end{gathered}

v 2=u 2+2as

v 2=0+2×9.8×100

v=√ 1960

hope this helps you

Answer 2

ANSWER:

We have to find it's speed (v)

• The stone is dropped from a cliff so its initial velocity,u will be 0
• Distance,s =100m
• acceleration due to gravity,g=9.8m/s²

Now applying formula to find Final velocity:-

☆ v²=u²+2gs

➠v²=(0)²+2(9.8)(100)

➠v²=2(9.8)(100)

➠v=√1960

So final velocity is √1960m/s