Question

A stone is dropped freely from the top of a tower and reaches the ground in 4 s. (Taking g = 10 m/s2
)
Calculate the height of the tower​

Answer 1

Answer :-

80m

Explanation :-

Given :

Time,t => 4s

Acceleration due to gravity,a => 10m/s^2

Initial velocity,u => 0m/s

To Find :

Height of the tower = ?

Solution :

According to the second law of the motion,

$\sf{}\bf{s=ut+\dfrac{1}{2}at^2}$

Put their values and solve for “s”

$\sf{}\implies s=0\times 4+\dfrac{1}{2}\times 10\times 4^2$

$\sf{}\implies s=\dfrac{1}{2}\times 10\times16$

$\sf{}\implies s=\dfrac{1}{1}\times 5\times16$

$\sf{}\therefore s=80m$

Therefore,height of the tower is equal to 80m

Answer 2

Given ,

• Initial velocity (u) = 0 m/s
• Time (t) = 4 sec
• Acceleration (a) = 10 m/s²

We know that , the Newton's second equation of motion is given by

$\boxed{ \tt{s = ut + \frac{1}{2}a {(t)}^{2} }}$

Thus ,

s = 0(4) + 1/2 × 10 × (4)²

s = 5 × 16

s = 80 m

Therefore , the height of tower is 80 m

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