At high altitude, a body explodes at rest into two equal fragment… - Vidyadip

MCQ

At high altitude, a body explodes at rest into two equal fragments with one fragment receiving horizontal velocity of $10 \mathrm{~m} / \mathrm{s}$. Time taken by the two radius vectors connecting point of explosion to fragments to make $90^{\circ}$ is

A
$10 \mathrm{~s}$
B
$4 s$
✓
$2 s$
D
$1 s$

✓

Answer

Correct option: C.

$2 s$

As the body at rest explodes into two equal parts, they acquire equal velocities in opposite directions according to conservation of momentum.
When the angle between the radius vectors connecting the point of explosion to the fragments is $90^{\circ}$, each radius vector makes an angle $45^{\circ}$ with the vertical.
To satisfy this condition, the distance of free fall $A D$ should be equal to the horizontal range in same interval of time.
$A D=D B$
$A D=0+\frac{1}{2} \times 10 t^2=5 t^2$
$ D B=u t=10 t $
$ \therefore 5 t^2=10 t \Rightarrow t=2 sec $

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Explore more

More "MCQ" from Surface Tension→Surface Tension — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

Consider the acceleration, velocity and displacement of a tennis ball as it falls to the ground and bounces back. Directions of which of these changes in the process

Find the maximum velocity for skidding for a car moved on a circular track of radius $100 m$. The coefficient of friction between the road and tyre is 0.2

The ratio of the wavelengths for $2 \rightarrow 1$ transition in $L i, H e$ and $H$ is

A rectangular coil of $20$ turns and area of cross- section $25 s q \mathrm{~cm}$ has a resistance of $100 \mathrm{ohm}$. If a magnetic field which is perpendicular to the plane of the coil changes at the rate of 1000 Tesla per second, the current in the coil is

A mass $M$ is suspended from a spring of negligible mass. The spring is pulled a little and then released so that the mass executes S.H.M. of time period $T$. If the mass is increased by $m$, the time period becomes $5 T / 3$. Then the ratio of $m / M$ is

Self induction of a solenoid is

During an adiabatic expansion of $2$ moles of a gas, the change in internal energy was found $-50.$ The work done during the process is

A body weight $W$ newton at the surface of the earth. Its weight at a height equal to half the radius of the earth will be

Work function of a metal is $2.1 \mathrm{eV}$. Which of the waves of the following wavelengths will be able to emit photoelectrons from its surface

A manometer connected to a closed tap reads $4.5 \times 10^5$ pascal. When the tap is opened the reading of the manometer falls to $4 \times 10^5$ pascal. Then the velocity of flow of water is