Physics, asked by archanaxx, 1 year ago

a stone is dropped from the top of a tower 100 m high.the stone peneterares in the sand on the ground through a distance of 2m. calculate the retardation of the stone

Answers

Answered by DSamrat
16
Hey.

Here is the answer.

s = 100 m

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

so, v^2 = 2 × 10 × 100

or, v^2 = 2000

or, v = √2000 m/s

So the stone hits the send with a velocity of √2000 m/s

Now, s = 2 m

let retardation be a

u = √2000 , v = 0

so, v^2 - u^2 = 2as

or, 0 - 2000 = 2×a×2

or, a = - 2000/4 = -500 m/s^2

So, retardation is -500 m/s^2.

Thanks.


archanaxx: why you took u=√2000, when firstly you showed v=√2000 by the 3rd equation of motion
DSamrat: as the stone hit sand with v= √2000 but then it penetrated into ground for further 2m so there i considered √2000 as intial velocity and 0 as final velocity as it stops(0) after 2m into the sand.
Answered by Adityaadidangi
5
from 100m of hight
speed just before striking with ground
= √(2×g×100)
u = √2000


by using formula
v² = u² + 2as

0 = 2000 - 2×a×2
500 = a


retardation = 500m/s²


hope it helps you

Adityaadidangi: as it comes from hight 100m
Adityaadidangi: speed of any object dropped from rest
Adityaadidangi: u = √2gh
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