Question

from the top of a tower a stone is projectee upwards and it reach the ground after 5 sec, the initial velocity of the particle is 12m/s , find the height​

Answer 1

Answer:

36/5

Explanation:

it is a projectile motion. so equation is h equals u square by 2g

Answer 2

Answer:

30 m

Explanation:

$\underline{\bigstar\:\textsf{Given:}}$

• Time (t) = 5 s
• Initial velocity (u) = 12 m/s

$\underline{\bigstar\:\textsf{To\:find:}}$

• Height (h) = ?

$\underline{\bigstar\:\textsf{Solution:}}$

We know, Newton's 2nd equation of motion i.e, $\blue{\tt{s\:=\:ut\:+\:\dfrac{1}{2}at^2}}$

Here, we don't know the acceleration (a), we know $\green{\tt{a\:=\:\dfrac{v-u}{t}}}$

$\longrightarrow\:\sf{a\:=\:\dfrac{0\:-\:12}{5}}$

$\:$

$\longrightarrow$ a = -2.4 m/s²

Now, the distance (s).

$\::\implies\:\sf{s\:=\:12\:×\:5\:+\:\dfrac{1}{2}\:×\:-2.4\:×\:(5)^2}$

$\:$

$\::\implies$ s = 60 - 1.2 × 25

$\:$

$\::\implies$ s = 60 - 30

$\:$

$\::\implies$ s = 30 m

$\:$

$\large:\implies\boxed{\sf\purple{s\:=\:30\:m}}$

---------------------------------------------------

$\underline{\bigstar\:\textsf{Verification:}}$

$\implies$ s = ut + ½at²

$\implies$ 30 = 12 × 5 + ½ × -2.4 × (5)²

$\implies$ 30 = 60 - 1.2 × 25

$\implies$ 30 = 60 - 30

$\implies$ 30 = 30

LHS = RHS. Hence, verified.