MCQ
A particle is projected from ground in vertical upward direction at $t = 0$, with initial velocity $48\, m/s$ and the distance travelled by particle in $5^{th}$ second is......$m$ $(g = 10\, m/s^2)$
- A$3$
- B$115$
- ✓$3.4$
- D$2.8$
✓
Answer
Correct option: C.
$3.4$
c
$5^{\text {th }}$ sec $\Rightarrow t=4 \rightarrow t=5$
$5^{\text {th }}$ sec $\Rightarrow t=4 \rightarrow t=5$
$\mathrm{S}_{4 \rightarrow 8}=$ Displacement in last $0.8\, sec$ of upward journey
$\mathrm{S}=\mathrm{vt}-\frac{1}{2} \mathrm{a}_{\mathrm{y}} \mathrm{t}^{2}, \mathrm{v}=0$
Assuming upward direction to be positive $(+i v e)$
$a_y=-g$
$S_{4 \rightarrow 4.8}=\frac{1}{2} \times g \times(0.8)^{2}=5 \times 0.64$
$\begin{aligned} \mathrm{S}_{4.8 \rightarrow 5}=& \mathrm{ut}+\frac{1}{2} \mathrm{at}^{2} \\ &=0+\frac{1}{2} \times 10 \times(0.2)^{2}=5 \times 0.04 \end{aligned}$
$\mathrm{S}_{4 \rightarrow 5}=5 \times 0.68=\frac{17}{5} \mathrm{m}$
Need a full question paper?
Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.
Explore more
Similar questions
The frequency of $1^{st}$ line of Balmer series in ${H_2}$ atom is ${\nu _0}$. The frequency of line emitted by singly ionised He atom is
→If a source of power $4\ kW$ produces $10^{20}$ photons/second , the radiation belongs to a part of the spectrum called
→Two solid conductors are made up of same material, have same length and same resistance. One of them has a circular cross section of area $A_{1}$ and the other one has a square cross section of area $A_{2}$. The ratio $\frac{A _{1}}{A _{2}}$ is
→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 body of mass ($2 {M}$) splits into four masses $\{{m}, {M}-{m}, {m}, {M}-{m}\}$, which are rearranged to form a square as shown in the figure. The ratio of $\frac{{M}}{{m}}$ for which, the gravitational potential energy of the system becomes maximum is ${x}: 1$. The value of $x$ is ..... .
→Adiabatic modulus of elasticity of a gas is $2.1 \times {10^5}N/{m^2}.$ What will be its isothermal modulus of elasticity $\left( {\frac{{{C_p}}}{{{C_v}}} = 1.4} \right)$
→forceA particle moves with constant speed $v$ along a circular path of radius $r$ and completes the circle in time $T$. The acceleration of the particle is
→Two inductors $L_1$ (inductance $1 \mathrm{mH}$, internal resistance $3 \Omega$ ) and $L_2$ (inductance $2 \mathrm{mH}$, internal resistance $4 \Omega$ ), and a resistor $R$ (resistance $12 \Omega$ ) are all connected in parallel across a $5 \mathrm{~V}$ battery. The circuit is switched on at time $t=0$. The ratio of the maximum to the minimum current $\left(I_{\max } / I_{\min }\right)$ drawn from the battery is
→The $r.m.s.$ velocity will be greater for
→The masses of blocks A and B are $m$ and $M$ respectively. Between $A$ and $B$, there is a constant frictional force $F$ and $B$ can slide on a smooth horizontal surface. A is set in motion with velocity while $B$ is at rest. What is the distance moved by A relative to $B$ before they move with the same velocity?
→