Question

A man on the 14 th floor of a building sees a bucket (dropped by a window washer) passing his window and notes that it hits the ground 1 second later. Assuming a floor is 4.9 meters high (and neglecting air friction), from what floor was the bucket dropped?

Answer 1

Answer:

The bucket was the dropped from 56 th floor.

Explanation:

Given that,

Height of floor = 4.9 m

Height of 14 floor = 68.6 m

Time taken = 1 sec

We need to calculate the speed of the bucket

Using equation of motion

$s=ut+\dfrac{1}{2}gt^2$

Put the value into the formula

$68.6=v\times1+\dfrac{1}{2}\times9.8\times(1)^2$

$v=68.6-\dfrac{1}{2}\times9.8\times(1)^2$

$v=63.7\ m/s$

We need to calculate the time

Using equation of motion

$v=u+gt$

$t=\dfrac{v}{g}$

Put the value into the formula

$t=\dfrac{63.7}{9.8}$

$t=6.5\ sec$

We need to calculate the distance

Using equation of motion

$s=ut+\dfrac{1}{2}gt^2$

$s=0+\dfrac{1}{2}gt^2$

Put the value into the formula

$s=\dfrac{1}{2}\times9.8\times(6.5)^2$

$s=207.025\ m$

We need to calculate the number of floor

$n=\dfrac{s}{h_{f}}$

Put the value into the formula

$n=\dfrac{207.025}{4.9}$

$n=42.25\approx42$

The bucket was the dropped from

$f=14+42= 56$

Hence, The bucket was the dropped from 56 th floor.