Question

A hiker stands on the edge of a cliff 490 m
above the ground and throws a stone
horizontally with speed ground and throws of
15 m s!. The time taken by the stone to reach
the ground is
(a) 5 s (b) 10 s (c) 12 s (d) 15 s​

Answer 1

$\huge\underline{\underline{\bf \orange{Question-}}}$

A hiker stands on the edge of a cliff 490m above the ground and throws a stone horizontally with speed ground and throws of 15 m/s. The time taken by the stone to reach the ground is

$\huge\underline{\underline{\bf \orange{Solution-}}}$

$\large\underline{\underline{\sf Given:}}$

• H = 490m
• v = 15m/s

$\large\underline{\underline{\sf To\:Find:}}$

• Time taken by stone to reach the ground (t)

We know that ,

✪$\large{\boxed{\bf \blue{t=\sqrt{\dfrac{2H}{g}}} }}$

$\implies{\sf t = \sqrt{\dfrac{2×490}{g}} }$

$\implies{\sf t = \sqrt{\dfrac{980}{9.8}} }$

$\implies{\sf t = \sqrt{100}}$

$\implies{\sf t = 10\:s }$

$\huge\underline{\underline{\bf \orange{Answer-}}}$

Option (b) 10s

The time taken by the stone to reach

the ground is ${\bf \red{10s}}$.

Answer 2

Answer:

____________

B. 10 s

____________