Question

A stone is thrown in a vertically upward direction with the velocity of 15 m per 2nd sq. If the acc. Of the stone during its motion is 10m per second square in a downward direction what will be the height attained by the stone and how much time it will take to reach there

Answer 1

Given that, a stone is thrown in a vertically upward direction with the velocity of 15 m/s. Here, the initial velocity i.e. u of the stone is 15 m/s.

Also, the stone during its motion is 10m per second square in a downward direction.

We have to find the height attained by the stone and time taken by the stone.

Using the First Equation Of Motion,

v = u + at

Take acceleration due to gravity as -10 m/s². (As it is against the gravity or in the opposite direction of u)

At highest point, final velocity will be 0 m/s.

0 = 15 + (-10)t

-15 = -10t

15/10 = t

1.5 = t

Therefore, time taken by the stone is 1.5 sec.

For distance, using the Second Equation Of Motion,

s = ut + 1/2 at²

Substitute the known values,

s = (15)(1.5) + 1/2 × (-10) × (1.5)²

s = 22.5 + (-5) × 1.5 × 1.5

s = 22.5 -11.25

s = 11.25

Therefore, the height attained by the stone is 11.25 m.

Answer 2

HEYA❇️❇️

#ANSWER

⏺️ Given √√

• Initial velocity of stone ( u ) => + 15 m/s

• Acceleration due to gravity acting downwards ( g ) => - 10 m/s^2

• Final velocity of stone ( v ) => 0 m/s { As the stone finally stops. )

⏺️ TO FIND √√

• Height attained by stone (s ) = ?
• Time taken to reach there (t ) = ?

⏺️ SOLUTION √√

{ 1 } Since , it is a case of uniformly accelerated motion, We use Kinematics third equation :

v^2 - u ^2 = 2 a s ,

{ where , s = height / displacement , u = initial velocity , a = acceleration due to gravity }

Putting all the given values in above equation,

We get ,

( 0 ) ^2 - ( 15 ) ^2 = 2 ( - 10 ) ( s )

- 225 = (- 20 ) ( s )

S ( height attained ) = - 225 / - 20

S = 11.25 m

Hence , Height attained by stone = > 11.25 m .

{ 2 } To Find Time taken , we use Kinematics first equation :

v = u + g t

Substituting all the values in above equation : we get √√

0 = 15 + ( - 10 ) ( t )

0 = 15 - 10t

10 t = 15

t = 15 / 10 = 1.5s

Hence , the Time taken by stone to reach certain height is 1.5 seconds.

⏹️ FINAL ANSWER √√

✔️Total height attained = 11.25m

✔️ Total time to reach = 1.5 s.

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THANKS !!!