Question

what is meant by free fall? A ball is thrown vertically upward with a velocity of 49m/s. calculate ¡)the maximum height to which it reaches ¡¡) the total time it takes to return to the surface of the earth. [g= 9.8 m/s2]​

Answer 1

free fall can be described as the falling of a object in which no external force is applied and it continuously fall down only due to the acceleration of gravity of Earth.

¡) by $v^2 - u^2 = 2gs$

since at the top most the ball would stop and started going down so the final velocity at the top most point would be '0'.

$0^2 - 49^2 = 2×-9.8×s$

the 'g' is taken negative because the acceleration is against gravity as it thrown upward.

$-49^2 = -19.6s$

$s = \frac{-2401}{19.6}$

$s = 122.5 m$

¡¡) now the from the formula

$a = \frac{v-u}{t}$

$g×t = v-u$

since in the time of free fall the acceleration is the

"acceleration due to gravity"

$-9.8t = -49$

$t = \frac{-49}{-9.8}$

$t = 5\:sec$

so same time would be taken to reach the ground after coming to the top most point so total time is

$5+5\:=\:10\:sec$

Answer 2

_/\_Hello mate__here is your answer--

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v = 0 m/s and

u = 49 m/s

During upward motion, g = − 9.8 m s^−2

Let h be the maximum height attained by the ball.

using

v^2 − u^2 = 2h

⇒ 0^2 − 49^2 = 2(−9.8)ℎ

⇒ ℎ =49×49/ 2×9.8 = 122.5

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Let t be the time taken by the ball to reach the height 122.5 m, then according to the equation of motion

v= u + gt

=>0 = 49 + (−9.8) t

⇒t 9.8 = 49

⇒ t= 49/9.8 =5 s

But, Time of ascent = Time of descent

Therefore, total time taken by the ball to return

= 5 + 5 = 10

I hope, this will help you.☺

Thank you______❤

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