Question

can u please with this question​

Answer 1

Answer:

(1) 0.3 seconds

Explanation:

Given :

• Initial velocity of balloon = u = 0 m/s

• Acceleration of the balloon = a = 2 m/s²

• Time = t = 1 second

• Stone is dropped then

To find :

• Time taken by the stone to reach the ground

Now let us find height covered by balloon, using second equation of motion :

S=ut+½×at²

S=0×1+½×2×1²

S=0+1

S=1 metre

Now using first equation of motion for finding final velocity :

V=u+at

V=0+2×1

V=2 m/s

So the initial velocity of Balloon will be 2 m/s as the velocity will be transferred

u = 2 m/s

S = 1 metre

a = 10 m/s² (gravity)

Using second equation of motion :

1=2×t+½×10×t²

1=2t+5t²

5t²+2t-1=0

By solving the quadratic equation :

t = 0.28.. ≈ 0.3 seconds

Hence (1) St option is correct

Answer 2

Answer :

Given that balloon started rising from ground from rest with an upward acceleration of 2 m/s² . Just after 1 second a stone is dropped from it.

We have to find time taken by stone to strike the ground.

From data we have :

Initial speed (u) = 0 m/s

Acceleration (a) = 2 m/s²

Time (t) = 1 s

Now using 2nd equation of motion :

→ h = ut + ½ gt²

→ h = 0 × 1 + ½ × 2 × 1²

→ h = 1 × 1

→ h = 1 m

Height attained by balloon = 1 m

Now finding final speed of balloon :

→ v = u + at

→ v = 0 + 2 × 1

→ v = 0 + 2

→ v = 2 m/s

As the final speed of balloon is 2 m/s, that means the initial speed of stone = 2 m/s

Now stone will have to cross 1 m height to reach ground. And as it will strike ground so, final speed of stone (v) = 0 m/s

Gravitational acceleration (g) = 10 m/s²

Now using 2nd equation of motion :

→ h = ut + ½ gt²

Substituting values,

→ 1 = 2t + ½ × 10 × t²

→ 1 = 2t + 5t²

→ 5t² + 2t - 1 = 0

Solving the quadratic equation we get ,

→ t = 0.3 seconds. (Approx.)

∴ Time taken by stone to reach ground = 0.3 seconds. (Approx.)

So, correct answer : (1) 0.3 s