A body freely falling from rest has a velocity ‘v’ after it falls through a height &lsqu

English

Gujarati

Hindi

2.Motion in Straight Line

hard

A body freely falling from the rest has a velocity $‘v’$ after it falls through a height $‘h’$. The distance it has to fall down for its velocity to become double, is

A

$2h$

B

$4h$

C

$6h$

D

$8h$

Solution

(b) Let at point $A$ initial velocity of body is equal to zero

for path $AB$ : ${v^2} = 0 + 2gh$…(i)

for path $AC $ : ${(2v)^2} = 0 + 2gx$

$4{v^2} = 2gx$…(ii)

Solving (i) and (ii)

$x = 4h$

Standard 11

Physics

Share

Similar Questions

A boy standing at the top of a tower of $20\, m$ height drops a stone . Assuming $g = 10 \,ms^{-2,}$ the velocity with which it hits the ground is………$ms^{-1}$

easy

(AIPMT-2011)

A boy is standing on top of a tower of height $85 \,m$ and throws a ball in the vertically upward direction with a certain speed. If $5.25$ s later he hears the ball hitting the ground, then the speed with which the boy threw the ball is ………. $m / s$ (take, $g=10 \,m / s ^2$ and speed of sound in air $=340 \,m / s$ )

hard

(KVPY-2015)

A ball is thrown upward with speed $10 \,m / s$ from the top of the tower reaches the ground with a speed $20 \,m / s$. The height of the tower is ……… $m$ [Take $g=10 \,m / s ^2$ ]

easy

A balloon starts rising from the ground with an acceleration of $1.25\, m/s^2$ after $8\,s$, a stone is released from the balloon. The stone will ($g = 10 \,m/s^2$)

hard

When a ball is thrown up vertically with velocity ${V_o}$, it reaches a maximum height of '$h$'. If one wishes to triple the maximum height then the ball should be thrown with velocity

medium

(AIIMS-2005)