Question

A stone falls freely from rest from a height h and it travels a distance 9h/25 in the last second . Find the value of h​

Answer 1

Answer:

Explanation:

H = 1/2 gt^2

Snth =u+ a/2(2n-1)

9h/25 =1/2g(2t-1)

Solving t = 5 s h = 125 m

Mark as brainliest pls

Answer 2

Explanation:

$\mathfrak{\huge{\orange{\underline{\underline{Answer :}}}}}$

Given

• distance covered in last second = 9h/25

To find

• value of h

Procedure

We know that ,

$t = \sqrt{ \frac{2h}{g} } - - - - eqn(1)$

Given that the body describes 9h/25 in the last second.

So, in (t-1) seconds it covers a distance

of h - 9h/25

= 16h/25

We know that t = √2h/g

Put h = 16h/25 and t = t - 1

$t - 1 = \sqrt{ \frac{2( \frac{16h}{25} )}{g} }$

$t - 1 = \sqrt{ \frac{32h}{25g} } - - (2)$

Divide eqn(1) by (2)

$\frac{t}{t - 1} = \frac{ \sqrt{ \frac{2h}{g} } }{ \sqrt{ \frac{32h}{25} } }$

$\frac{t}{t - 1} = \sqrt{ \frac{2h}{g} \times \frac{25g}{36h} }$

$\frac{t}{t - 1} = \sqrt{ \frac{25}{16} }$

$\frac{t}{t - 1} = \frac{5}{4}$

on cross multiplication,

$5t - 5 = 4t$

t = 5s

Now substitute t=5 in equation 1

$5 = \sqrt{ \frac{2h}{g} }$

We know that g= 10m/s^2

$5 = \sqrt{ \frac{2h}{10} }$

Squaring on both sides,

$25 = \frac{2h}{10}$

2h = 25 × 10

2h = 250

$h = \frac{250}{2}$

$h = 125m$

HOPE IT HELPS YOU