Question

A ball is dropped from the top of a 20m high tower. If it's velocity is increasing with an accelerate of 10m/s² then at what speed will the ball hit the ground? How much time will it take to hit the ground?​

Answer 1

Answer:

ᴿᴱᶠᴱᴿ ᵀᴴᴱ ᴬᵀᵀᴬᶜᴴᴹᴱᴺᵀ

ᴴᴼᴾᴱ ᴵᵀ ᴴᴱᴸᴾˢ ◉‿◉

Answer 2

GivEn :

• Initial velocity of the ball (u) = 0 m/s

• Distance from the top of a tower (s) = 20 m

• Acceleration of the ball (a) = 10 m/s²

To find :

• Final velocity or the speed required to hit the ground and the time taken = ?

SoluTion :

We'll solve this question by using the equations of motion.

Eqn used : v² = u² + 2as ; v = u + at

Substituting the values,

$\implies \: \: \sf{v}^{2} - {u}^{2} = 2as$

$\implies \: \: \sf{v}^{2} - {0}^{2} = 2 \times 10 \times 20$

$\implies \: \: \sf{v}^{2} = 400$

$\implies \: \: \sf v = 20 \: m {s}^{ - 1}$

Now,

Time required by the ball to hit the ground :

$\implies \sf \: \: v = u + at$

$\implies \sf \: \: 20 = 0+ 10 \times t$

$\implies \sf \: \: 20 = 10t$

$\implies \sf \: \: t = \cancel\dfrac{20}{10}$

$\implies \sf \: \: t = 2 \: s$

Therefore, the speed required to hit the ground is 20 m/s and the time taken to hit the ground is 2 s .