A man throws balls with the same speed vertically upwards one aft… - Vidyadip

MCQ

A man throws balls with the same speed vertically upwards one after the other at an interval of 2 seconds. What should be the speed of the throw so that more than two balls are in the sky at any time (Given $g=9.8 m / s ^2$ )

A
At least $0.8 m / s$
B
Any speed less than $19.6 m / s$
C
Only with speed $19.6 m / s$
✓
More than $19.6 m / s$

✓

Answer

Correct option: D.

More than $19.6 m / s$

(d) Interval of ball throw $=2 \ \mathrm{sec}$.If we want that minimum three (more than two )ball remain in air then time of flight of first ball must be greater than $4\mathrm{sec}$
$T>4 \mathrm{sec} $ $\frac{2 u}{g} >4\mathrm{sec} \Rightarrow u > 19.6\mathrm{~m} \mathrm{s}$ for $u=19.6$.
First ball will just strike the ground (in sky) Second N ball will (in sky)Third ball will be at point of projection or at ground (not in sky) (a) The distance covered by the ball during the last $t$ seconds of its upward motion $=$ Distance covered by it in first $t$ seconds of its downward motionFrom $h=u t+\frac{1}{2} g t^2$

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 Motion in One Dimension→Motion in One Dimension — all question types→JEE physics STD 12 Science question papers→CBSE Board STD 12 Science question papers→CBSE Board question paper generator→

Similar questions

In short wave communication waves of which of the following frequencies will be reflected back by the ionospheric layer, having electron density $10$ per $m$

Density of ice is $\rho$ and that of water is $\sigma$. What will be the decrease in volume when a mass $M$ of ice melts

The unit of $L / R$ is (where $L=$ inductance and $R=$ resistance)

A force of $5 N$ acts on a particle along a direction making an angle of $60^{\circ}$ with vertical. Its vertical component be

Which of the following pairs is wrong

$62.5 \times 10^{18}$ electrons per second are flowing through a wire of area of cross-section $0.1 \mathrm{~m}^2$, the value of current flowing will be

A body of $5 \mathrm{~kg}$ weight kept on a rough inclined plane of angle $30^{\circ}$ starts sliding with a constant velocity. Then the coefficient of friction is (assume $g=10 \mathrm{~m} / \mathrm{s}^2$ )

In a capillary tube, water rises to $3 \mathrm{~mm}$. The height of water that will rise in another capillary tube having one $-$ third radius of the first is

$1 \mathrm{~cm}^3$ of water at its boiling point absorbs $540$ calories of heat to become steam with a volume of $1671 \mathrm{~cm}^3$.If the atmospheric pressure $=1.013 \times 10^5 \mathrm{~N} / \mathrm{m}^2$ and the mechanical equivalent of heat $=4.19 \mathrm{~J} /$ calorie, the energy spent in this process in overcoming intermolecular forces is

An electron of charge $e$ moves in a circular orbitof radius $r$ around the nucleus at a frequency $v$. The magnetic moment associated with the orbital motion of the electron is