Question

a stone is dropped from a hundred meter high. How long does it take to fall
a. at first 50 m
b. second 50 m​

Answer 1

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• a stone is dropped from a hundred meter high. How long does it take to fall
• a. at first 50 m
• b. second 50 m

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$\:\:\:\: \: \: \: \: \: \: \: \: \: \: \large\mathfrak{\large\mathcal{\bf{\boxed{\large\mathcal{a...3.194sec....b...0.964 sec}}}}}$

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$\:\: \underline{\underline{\bf{\large\mathfrak{~~solution1~~}}}}$

using the formula...

$s = ut + \frac{1}{2} at {}^{2}$

here....a=g=9.8m/s²

initial velocity (u)=0

now ....for the first 50 metres...

$50 = 0(t) + \frac{1}{2} \times 9.8 \times t {}^{2} \\ = > t {}^{2} = \frac{100}{9 .8} \\ = > t = \sqrt{ \frac{100}{9.8} } \\ = > t = 3.194 \: \: sec$

now ....the the time for total journey...i.e.of 100m

$100 = 0(t) + \frac{1}{2} \times 9.8 \times t {}^{2} \\ = > t = \sqrt{ \frac{200}{9.8} } = 4.518 \: \: sec$

so the time taken by the stone for the second 50 metre is

$= (4.158 - 3.194) \: \: sec \\ = 0.964 \: \: sec$

$\huge\mathcal\green{\underline{hope\:\: this\:\: helps\:\: you}}$