MCQ
Two balls with same mass and initial velocity, are projected at different angles in such a way that maximum height reached by first ball is 8 times higher than that of the second ball. $T_{1}$ and $T_{2}$ are the total flying times of first and second ball, respectively, then the ratio of $T_{1}$ and $T_{2}$ is :
  • $2 \sqrt{2}: 1$
  • B
    $2: 1$
  • C
    $\sqrt{2}: 1$
  • D
    $4: 1$

Answer

Correct option: A.
$2 \sqrt{2}: 1$
(A) $2 \sqrt{2}: 1$
Given, $\left( H _{\max }\right)_1=8 \times\left( H _{\max }\right)_2$
$
\frac{u^2 \sin ^2 \theta_1}{2 g}=8 \times \frac{u^2 \sin ^2 \theta_2}{2 g}
$
$\begin{array}{l}\Rightarrow \sin \theta_1=2 \sqrt{2} \sin \theta_2 \\ \frac{T_1}{T_2}=\frac{2 u \sin \theta_1 / g }{2 u \sin \theta_2 / g }=\frac{\sin \theta_1}{\sin \theta_2}=2 \sqrt{2}\end{array}$

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

Similar questions

A transformer having efficiency of $90\%$ is working on $200\, V$ and $3\, kW$ power supply. If the current in the secondary coil is $6\, A,$ the voltage across the secondary coil and the current in the primary coil respectively are
$n$ drops of $a$ liquid, each with surface energy $E$, joining to form a single drop
Find the ratio of time periods of two identical springs if they are first joined in series $\&$ then in parallel $\&$ a mass $m$ is suspended from them :
Match list-I with list-II :
 List-I List-II
(A)Kinetic energy of planet(I)$-\frac{ GMm }{ a }$
(B)Gravitation Potential energy of Sun-planet system.(II)$\frac{ GMm }{2 a }$
(C)Total mechanical energy of planet(III)$\frac{ Gm }{ r }$
(D)Escape energy at the surface of planet for unit mass object(IV)$-\frac{ GMm }{2 a }$
(Where a = radius of planet orbit, r = radius of 
planet, M = mass of Sun, m = mass of planet) 
A $N-P-N$ transistor is connected in common emitter configuration (see figure) in which collector voltage drop across load resistance $(800 \; \Omega)$ connected to the collector circuit is $0.8 \;V$. The collector current is .............. $mA$
$A$ circular planar wire loop is dipped in a soap solution and after taking it out, held with its plane vertical in air. Assuming thickness of film at the top very small, as sunlight falls on the soap film, & observer receive reflected light
The field due to a magnet at a distance $ R$  from the centre of the magnet is proportional to
Two identical solid spheres each of mass $2\,kg$ and radii $10\,cm$ are fixed at the ends of a light rod. The separation between the centres of the spheres is $40\,cm$. The moment of inertia of the system about an axis perpendicular to the rod passing through its middle point is $........... \times 10^{-3}\,kg - m ^2$
A ray of light is incident on a thick slab of glass of thickness $t$ as shown in the figure.  The  emergent ray is parallel to the incident ray but displaced sideways by a distance $d$. If  the angles are small then $d$ is
$X $ and $Y$ are large, parallel conducting plates closed to each other. Each face has an area $A$. $X$ is given a charge $Q$. $Y$ is without any charge. Points $A, B$ and $C$ are as shown in figure.