Question

A stone is dropped from the roof of the building takes 4 sec to reach ground calculate the height of the building​

Answer 1

Answer:

here it is related with uniform acceleration

(s=ut+ 1/2at²) (kinematic equation)

here,the stone is dropped. therefore initial velocity,u is zero.

s=1/2at²

here, acceleration≈acc. due to gravity (9.8≈10)

s=1/2gt²

s=1/2×10×4²=10×16/2=10×8 =80 m

Answer 2

Solution :-

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U => 0

A = g => 10 m/s

T => 4 s

S = ?

Using second equation of motion

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S = ut + 1/2* at^2

S = 0*4 + 1/2 * 10 * 4 * 4

S = 0 + 80

S = 80 meter

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