Vertical height of point P above ground is twice that of Q . A particle is projected downward with a

English

Gujarati

Hindi

2.Motion in Straight Line

hard

The vertical height of point $P$ above the ground is twice that of $Q$. A particle is projected downward with a speed of $5 m / s$ from $P$ and at the same time another particle is projected upward with the same speed from $Q$. Both particles reach the ground simultaneously, then

A

$P Q=30\,m$

B

time of flight of stones $=3\,s$

C

Both $(a)$ and $(b)$ are correct

D

Both $(a)$ and $(b)$ are wrong

Solution

(c)

$-h=5 t-5 t^2$ and $-2 h=-5 t-5 t^2$

From these two equations we get, $t=3\,s$ and $h=$ distance between $P$ and $Q=30\,m$.

Standard 11

Physics

Share

Similar Questions

A particle is dropped vertically from rest from a height. The time taken by it to fall through successive distances of $1\, m$ each will then be

hard

A body dropped from a height $h$ with an initial speed zero, strikes the ground with a velocity$3\,km/h$. Another body of same mass is dropped from the same height $h$ with an initial speed of $4\,km/h$ . Find the final velocity of second body with which it strikes the ground………$km/h$

medium

(AIPMT-1996)

A packet is dropped from a balloon which is going upwards with the velocity $12 \,m/s$, the velocity of the packet after $2$ seconds will be……..$m/s$

easy

A body projected vertically upwards with a velocity $u$ returns to the starting point in $4 \,seconds$. If $g = 10m/sec^2$, the value of $u$ is………$m/sec$

easy

A stone is dropped from the top of a building. When it crosses a point $5\, m$ below the top, another stone starts to fall from a point $25\, m$ below the top. Both stones reach the bottom of building simultaneously. The height of the building is ….. $m$.

hard

(JEE MAIN-2021)