Question

stone Falls from the top of the tower in 8 seconds how much time it will take to cover the first quarter of the distance starting from the top

Answer 1

time taken = 8 sec
initial velocity = 0 m/s
acceleration = 10 m/s^2
therefore distance covered ,
s = ut + 1/2 at^2
s= 0 * 8 + 1/2 *10 * 8^2
s = 5 * 64
s =  320 meter
there fore distance covered in the 1st quarter ,
320/4 = 80 m
distance = 80 meter
acceleration = 10 m/s
initial velocity = 0 m/s
therefore time taken,
s = ut + 1/2* at^2
80 = 0 * t +1/2 * 10 * t^2
80 = 5 t^2
80 / 5 = t^2
16 = t^2
√16 = t
4 = t
therefore time taken to travel the 1st quarter ( 80 meter ) = 4 seconds.
    i hope that this will help u..........................^_^

Answer 2

Answer:

Time taken by stone to cover first quarter of distance is 4 sec.

Explanation:

Given that :

• Time taken by stone to reach the ground 8 second

To find :

• Time taken by stone to cover first quarter of distance

Solution :

• Let, the stone be dropped from point A which is h meters above the ground.
• Time taken by stone to cover this distance is 8 seconds.
• Since the stone is dropped from rest its initial velocity is zero.
• From second equation of motion

$s = ut + \frac{1}{2} g {t}^{2} \\ h = \frac{1}{2}g {(8)}^{2} \\ h = 32g \\ g = \frac{h}{32} - - - (1)$

• Let, Time taken by stone to cover first quarter of distance be t'. Then,

$h' = \frac{1}{2} g {t'}^{2} \\ \frac{h}{4} = \frac{1}{2} (32h) {t'}^{2} \\ {t'}^{2} = 16 \\ t' = 4 \: sec$

• Hence, time taken by stone to cover first quarter of distance is 4 sec.