Download App

STD 11 - 5. work,energy,power and collision — NEET STD 11 Science — Question

Gujarat BoardEnglish MediumSTD 11 ScienceNEETSTD 11 - 5. work,energy,power and collision4 Marks
MCQ
Three blocks are initially placed as shown in the figure. Block $A$ has mass $m$ and initial velocity $v$ to the right. Block $B$ with mass $m$ and block $C$ with mass $4m$ are both initially at rest. Neglect friction. All collisions are elastic. The final velocity of block $A$ is
  • ✓
    $0.6v$ to the left
  • B
    $1.4v$ to the left
  • C
    $v$ to the left
  • D
    $0.4v$ to the right
✓

Answer

Correct option: A.
$0.6v$ to the left
a
since, $A$ and $B$ have same mass. So, after elastic collision, they interchange their velocity

$\therefore \mathrm{v}_{\mathrm{B}}=\mathrm{v}$

After collision between $\mathrm{B}$ and $\mathrm{C}$

$\mathrm{v}_{\mathrm{B}}=\left(\frac{\mathrm{m}-4 \mathrm{m}}{\mathrm{m}+4 \mathrm{m}}\right) \mathrm{v}+\left(\frac{2 \times 4 \mathrm{m} \times 0}{\mathrm{m}+4 \mathrm{m}}\right)=-\frac{3}{5} \mathrm{v}$

Again, collision takes place between $A$ and $B .$ So, velocity will be inter changed.

$\therefore v_{A}=\left(v_{B}\right)=\frac{3}{5} v$

in left ward direction.

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

NEET STD 11 Science question papers→Gujarat Board STD 11 Science question papers→Gujarat Board question paper generator→

Similar questions

$P$ is obtained by reductive ozonolysis of
→
The period of oscillation of a simple pendulum in the experiment is recorded as $2.63\, s, 2.56 s, 2.42\, s, 2.71\, s$ and $2.80 \,s$ respectively. The average absolute error is ......... $s$
→
A truck of mass $ 30,000kg$  moves up an inclined plane of slope $1$ in $100$  at a speed of $ 30 kmph$. The power of the truck is ................. $kW$ (given $g = 10m{s^{ - 1}})$
→
Let $T_{1}$ and $T_{2}$ be the energy of an electron in the first and second excited states of hydrogen atom, respectively. According to the Bohr's model of an atom, the ratio $T _{1}: T _{2}$ is
→
The magnetic field of a plane electromagnetic wave is given by

$\overrightarrow{ B }=2 \times 10^{-8} \sin \left(0.5 \times 10^{3} x +1.5 \times 10^{11} t \right) \hat{ j } T$ The amplitude of the electric field would be.

→
Which of the following does not give stable product with water
→
A block of mass $4\,kg$ is placed on a rough horizontal plane A time dependent force $F = kt^2$ acts on the block, where $k = 2\,N/s^2$. Coefficient of friction $\mu = 0.8$. Force of friction between block and the plane at $t = 2\,s$ is ....... $N$
→
A spring balance is attached to the ceiling of a lift. $A$ man hangs his bag on the spring  and the spring reads $49 \,N$, when the lift is stationary. If the lift moves downward with  an acceleration of $5\, m/s^2$, the reading of the spring balance will be .......... $N$
→
When phosphorus and antimony are mixed in zermaniun, then
→
Aball is thrown from a point on ground at some angle of projection. At the same time a bird starts from a point directly above this point of projection at a height $h$ horizontally with speed $u$. Given that in its flight ball just touches the bird at one point. Find the distance on ground where ball strikes
→