COMEDK · Physics · 7. Center of Mass Momentum and Collision
A shell of mass \(20 \mathrm{~g}\) is fired by a gun of mass \(100 \mathrm{~kg}\). If the shell leaves the gun with a speed of \(80 \mathrm{~ms}^{-1}\), then the speed of recoil of the gun is
- A \(3.2 \mathrm{cms}^{-1}\)
- B \(1.6 \mathrm{cms}^{-1}\)
- C \(1 \mathrm{cms}^{-1}\)
- D \(2.4 \mathrm{cms}^{-1}\)
Answer & Solution
Correct Answer
(B) \(1.6 \mathrm{cms}^{-1}\)
Step-by-step Solution
Detailed explanation
Given, mass of shell, \(m_{s}=20 \mathrm{~g}=0.02 \mathrm{~kg}\) Mass of gun, \(m_{g}=100 \mathrm{~kg}\) Speed of shell, \(v_{s}=80 \mathrm{~m} / \mathrm{s}\) Let \(v_{g}\) be the speed of the recoil of gun, then according to law of conservation of linear momentum. Total initial…
See the Complete Solution
Get step-by-step explanations for this and 2.5 Lakh+ more JEE, NEET & CET questions.
- Unlock all solutions
- Practice the full chapter
- Track accuracy across PYQs
4.8 rated on Google Play · 14,000+ reviews
More questions from Physics
- An electric motor raises a mass of \(1.5 \mathrm{~kg}\), a distance of \(1.128 \mathrm{~m}\) in time of \(4.79 \mathrm{~s}\). Calculate the power to an appropriate significant figures.
(take \(g=9.81 \mathrm{~ms}^{-2}\))COMEDK 2024 Easy - Bodies P, Q, R, S are labelled as having charges \(Q_P = 0.5 \times 10^{-19}C\), \(Q_Q = 0.7 \times 10^{-19}C\), \(Q_R = 2.1 \times 10^{-19}C\), \(Q_S = 4.8 \times 10^{-19}C\) respectively. Select the body having the correct charge.
[Given electronic charge \(= e = 1.6 \times 10^{-19}C\)]COMEDK 2026 Easy - A source of light of wavelength \(5000 Å\) is placed at one end of a table \(2 \mathrm{~m}\) long and \(5 \mathrm{~mm}\) above its flat well polished top. The fringe width of the interference bands seen on a screen located at the end of the table isCOMEDK 2014 Hard
- The momentum of electrons having a wavelength \(2 Å\) (given, \(h=6.626 \times 10^{-34} \mathrm{~J}\)-s, \(\left.m=9.1 \times 10^{-35} \mathrm{~kg}\right)\) isCOMEDK 2015 Easy
- A spherical drop of capacitance \(1 \mu \mathrm{F}\) is broken into eight drops of equal radius. Then, the capacitance of each small drop isCOMEDK 2019 Hard
- The acceleration due to gravity at a height of \(7 \mathrm{~km}\) above the earth is the same as at a depth d below the surface of the earth. Then d isCOMEDK 2023 Medium
More PYQs from COMEDK
- Identify the correct values to be plotted in the graph, the slope of which can be used to determine the activation energy of a reaction.COMEDK 2026 Medium
-
The magnetic field at the centre of a wire loop formed by two semicircular wires of radii \(r_1\) = 3.14m and \(r_2\) = 6.28m and carrying a current of I =2A is:COMEDK 2026 Medium - Carbon forms two oxides which have different compositions. The equivalent mass of which remains constant?COMEDK 2020 Medium
- The rate of heat conduction in the given two metal rods having the same length is found to be the same when the temperature difference between the ends is kept \(30^{\circ} \mathrm{C}\) If the area of cross section of the first rod is \(8 \times 10^{-2} \mathrm{~m}^2\) then what will be area of cross section of the second rod? [ Given that the ratio of the thermal conductivity of the first rod to that of the second rod is \(1: 4\) ]COMEDK 2025 Medium
- The equation of the parabola with vertex at \((-1,1)\) and focus \((2,1)\) isCOMEDK 2016 Easy
- If \(M\) is the mass of the earth and \(R\) its radius, the ratio of the gravitational acceleration and the gravitational constant isCOMEDK 2017 Easy