JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A body of mass \(2\,kg\) makes an elastic collision with a second body at rest and continues to move in the original direction but with one fourth of its original speed. What is the mass of the second body? ................ \( \mathrm{kg}\)
- A \(1.5\)
- B \(1.2\)
- C \(1.8\)
- D \(1\)
Answer & Solution
Correct Answer
(B) \(1.2\)
Step-by-step Solution
Detailed explanation
By conseravtion of linear momentum; \(\begin{array}{l} 2{v_0} = 2\left( {\frac{{{v_0}}}{4}} \right) + mv \Rightarrow 2{v_0} = \frac{{{v_0}}}{2} + mv\,2\\ \Rightarrow \frac{{3{v_0}}}{2} = mv\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...\left( 1 \right) \end{array}\) Since…
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
- If frequency of electromagnetic wave is \(60 \mathrm{MHz}\) and it travels in air along \(\mathrm{z}\) direction then the corresponding electric and magnetic field vectors will be mutually perpendicular to each other and the wavelength of the wave (in \(\mathrm{m}\) ) is _______.JEE Mains 2024 Hard
- Two point charges \(q_1\,(\sqrt {10}\,\,\mu C)\) and \(q_2\,(-25\,\,\mu C)\) are placed on the \(x-\) axis at \(x = 1\,m\) and \(x = 4\,m\) respectively. The electric field (in \(V/m\) ) at a point \(y = 3\,m\) on \(y-\) axis is, [ take \({\mkern 1mu} {\mkern 1mu} \frac{1}{{4\pi {\varepsilon _0}}} = 9 \times {10^9}{\mkern 1mu} {\mkern 1mu} N{m^2}{C^{ - 2}}{\rm{ }}\) ]JEE Mains 2019 Hard
- Sixty four conducting drops each of radius \(0.02 m\) and each carrying a charge of \(5 \,\mu C\) are combined to form a bigger drop. The ratio of surface density of bigger drop to the smaller drop will be ............JEE Mains 2022 Medium
- The moment of inertia of a circular ring of mass \(M\) and diameter r about a tangential axis lying in the plane of the ring is :JEE Mains 2025 Easy
- In a series \(LCR\) circuit, the inductive reactance \(\left( X _{ L }\right)\) is \(10\, \Omega\) and the capacitive reactance \(\left( X _{ C }\right)\) is \(4\, \Omega\). The resistance \(( R )\) in the circuit is \(6\, \Omega\). The power factor of the circuit is :JEE Mains 2021 Medium
- The maximum error in the measurement of resistance, current and time for which current flows in an electrical circuit are \(1 \%, 2 \%\) and \(3 \%\) respectively. The maximum percentage error in the detection of the dissipated heat will beJEE Mains 2022 Easy
More PYQs from JEE Mains
- Consider a \(72\, cm\) long wire \(AB\) as shown in the figure. The galvanometer jockey is placed at \(P\) on \(A B\) at a distance \(x cm\) from \(A\). The galvanometer shows zero deflection. The value of \(x,\) to the nearest integer, is ..... \(cm\)
JEE Mains 2021 Medium - When a hydrogen atom going from \(\mathrm{n}=2\) to \(\mathrm{n}=1\) emits a photon, its recoil speed is \(\frac{\mathrm{x}}{5} \mathrm{~m} / \mathrm{s}\). Where \(\mathrm{x}=\) _______. (Use : mass of hydrogen atom\(\left.=1.6 \times 10^{-27 /} \ \mathrm{kg}\right)\)JEE Mains 2024 Hard
- If the domain of the function \(f(x)=\log _e\) \(\left(\frac{2 x+3}{4 x^2+x-3}\right)+\cos ^{-1}\left(\frac{2 x-1}{x+2}\right)\) is \((\alpha, \beta]\), then the value of \(5 \beta-4 \alpha\) is equal toJEE Mains 2024 Hard
- The pressure \(P_{1}\) and density \(d_{1}\) of diatomic gas \(\left(\gamma=\frac{7}{5}\right)\) changes suddenly to \(P _{2}\left(> P _{1}\right)\) and \(d _{2}\) respectively during an adiabatic process. The temperature of the gas increases and becomes \(......\) times of its initial temperature.\(\left(\right.\) given \(\left.\frac{ d _{2}}{ d _{1}}=32\right)\)JEE Mains 2022 Medium
- A value of \(\theta\) for which \(\frac{{2 + 3isin\;\theta }}{{1 - 2i\sin \theta }}\) is purely imaginary, is:JEE Mains 2016 Medium
- A thin convex lens and a thin concave lens are kept in contact and are co-axial. Which of the following statements is correct for this combination of two lenses ?JEE Mains 2026 Medium