A ball of mass 1 ,kg is projected with a velocity of 20 2 ,m / s … - Vidyadip

MCQ

A ball of mass $1 \,kg$ is projected with a velocity of $20 \sqrt{2}\,m / s$ from the origin of an $x y$ co-ordinate axis system at an angle $45^{\circ}$ with $x$-axis (horizontal). The angular momentum [In $SI$ units] of the ball about the point of projection after $2 \,s$ of projection is [take $g=10 \,m / s ^2$ ] ( $y$-axis is taken as vertical)

✓
$-400 \hat{k}$
B
$200 \hat{i}$
C
$300 \hat{j}$
D
$-350 \hat{j}$

✓

Answer

Correct option: A.

$-400 \hat{k}$

a
(a)

Time of flight $T=\frac{2 u \sin \theta}{g}=\frac{2(20 \sqrt{2}) \frac{1}{\sqrt{2}}}{10}=4$ second

$\Rightarrow$ After $2$ second particle will be at maximum height of the projectile $L=m v r_{\perp}$

$r_{\perp}=H_{\max }=\frac{u^2 \sin ^2 \theta}{2 g}=20 \,m$

So $L=(1)(20)(20)=400(-\hat{k})$

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 "M.C.Q (1 Marks)" from 6. system of particles and rotational motion→6. system of particles and rotational motion — all question types→Physics STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

The specific heat of a gas at constant volume is $21.2\, J/mole/°C.$ If the temperature is increased by $1°C$ keeping the volume constant, the change in its internal energy will be ...... $J$

A particle tied to one end of a string is being rotated in a vertical circle with constant frequency. The tension in the string at points $A, B, C$ and $D$ are $T_1, T_2, T_3$ and $T_4$ respectively Then

A physical quantity is $A = P^2/Q^3.$ The percentage error in measurement of $P$ and $Q$ is $x$ and $y$ respectively. Maximum error in measurement of $A$ is

Two particles are performing simple harmonic motion in a straight line about the same equilibrium point. The amplitude and time period for both particles are same and equal to $A$ and $T,$ respectively. At time $t=0$ one particle has displacement $A$ while the other one has displacement $\frac {-A}{2}$ and they are moving towards each other. If they cross each other at time $t,$ then $t$ is

The radii of two planets $A$ and $B$ are $R$ and $4 R$ and their densities are $\rho$ and $\rho / 3$ respectively. The ratio of acceleration due to gravity at their surfaces $\left(g_A: g_B\right)$ will be

$5\, g$ of ice at $0°C$ is dropped in a beaker containing $20\, g$ of water at $40°C.$ The final temperature will be........ $^oC$

At the highest point of the path of a projectile, its

A sniper fires a rifle bullet into a gasoline tank making a hole $53.0 m$ below the surface of gasoline. The tank was sealed at $3.10 atm$. The stored gasoline has a density of $660 kgm^{-3}$. The velocity with which gasoline begins to shoot out of the hole is........ $ms^{-1}$

The figure shows a process $AB$ undergone by $2$ moles of an ideal diatomic gas. The process $AB$ is in such a way that $VT =$ constant. $T_1 = 300 K $and $T_2 = 500 K$ ( $R = $ gas constant)

Four wires of identical length, diameters and of the same material are stretched on a sonometre wire. If the ratio of their tensions is $1 : 4 : 9 : 16$ then the ratio of their fundamental frequencies are