Question

A stone is thrown upward with a velocity
of 72 km/hr. If the air resistance
neglected find the height reached by it.​

Answer 1

$\huge \sf \bf \mathtt{ \red{hi \: mate}}$

Given :-

Initial Velocity (u) = 72 km/hr

Final Velocity (v) = 0 m/s

Acceleration due to gravity (g) = -10 m/s

To Find :-

The maximum height reached and time taken to reach the height.

$\large{ \blue{Solution}}$

★ First we have to convert Initial Velocity (u) 72 km/hr to m/s :

→ Initial Velocity (u) = 72 × 5/18

→ Initial Velocity (u) = 20 m/s

Now,by using first equation of motion we get :

⋗ v = u + at

⋗ 0 = 20 + (-10)t

⋗ 0 = 20 - 10t

⋗ -20 = -10t

⋗ t = -20 ÷ -10

⋗ t = 20 ÷ 10

⋗ t = 2 s

Now,by using second equation of motion we get :

⇢s = ut + ½ at²

⇢s = 20 × 2 + ½ × -10 × (2)²

⇢s = 40 + ½ × -10 × 4

⇢s = 40 -10 × 2

⇢s = 40 - 20

⇢s = 20 m

Therefore,

The maximum height reached by stone = 20 m

and time taken by it to reach the height = 2 s

Answer 2

Answer:

20.4meters

Explanation:

Therefore,

The correct answer is 20.4 meters.

HOPE THIS IS HELPFUL.