WBJEE · Physics · Laws of Motion
A smooth massless string passes over a smooth fixed pulley. Two masses \(m_{1}\) and \(m_{2},\left(m_{1}>m_{2}\right)\) are tied at the two ends of the string. The masses are allowed to move under gravity starting from rest. The total external force acting on the two masses is
- A \(\left(m_{1}+m_{2}\right) g\)
- B \(\frac{\left(m_{1}-m_{2}\right)^{2}}{m_{1}+m_{2}} g\)
- C \(\left(m_{1}-m_{2}\right) g\)
- D \(\frac{\left(m_{1}+m_{2}\right)^{2}}{m_{1}-m_{2}} g\)
Answer & Solution
Correct Answer
(B) \(\frac{\left(m_{1}-m_{2}\right)^{2}}{m_{1}+m_{2}} g\)
Step-by-step Solution
Detailed explanation
We know that Acceleration, \(a_{\mathrm{CM}}=\left(\frac{m_{1}-m_{2}}{m_{1}+m_{2}}\right)^{2} \times g\left(\because m_{1}>m_{2}\right)\) So, resultant external force.…
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
- Six vectors \(\vec{a}, \vec{b}, \vec{c}, \vec{d}, \vec{e}\) and \(\vec{f}\) have the magnitudes and directions indicated in the figure. Which of the following statements is true?
WBJEE 2025 Easy - Four identical plates each of area \(a\) are separated by a distance \(d\). The connection is shown below. what is the capacitance between \(P\) and \(Q ?\)
WBJEE 2013 Hard - A photon of wavelength 300 nm interacts with a stationary hydrogen atom in ground state. During the interaction, whole energy the photon is transferred to the electron of the atom. State which possibility is correst. (Consider, Plank constant \(=4 \times 10^{-15} eV_{s},\) velocity of light \(=3 \times 10^{8} \mathrm{m} / \mathrm{s},\) ionisation energy of hydrogen \(=13.6 \mathrm{eV}\) )WBJEE 2015 Hard
- The vectors \(\mathrm{A}\) and \(\mathrm{B}\) are such that \(|\mathbf{A}+\mathbf{B}|=|\mathbf{A}-\mathbf{B}| .\) The angle between the two vectors will beWBJEE 2016 Medium
- A spherical convex surface of power 5 dioptre separates object and image space of refractive indices \(1.0\) and \(\frac{4}{3}\) respectively. The radius of curvature of the surface isWBJEE 2021 Medium
- Two particles \(A\) and \(B\) having different masses are projected from a tower with same speed. \(A\) is projected vertically upward and \(B\) vertically downward. On reaching the groundWBJEE 2015 Medium
More PYQs from WBJEE
- For the two circles \(x^2+y^2=16\) and \(x^2+y^2-2 y=0\) there is / areWBJEE 2009 Hard
- If \(X\) is a random variable such that \(\sigma(X)=2.6\) then \(\sigma(1-4 x)\) is equal toWBJEE 2019 Easy
- Addition of excess potassium iodide solution to a solution of mereuric chloride gives the halide complexWBJEE 2013 Medium
- For air at room temperature, the atmospheric pressure is \(1.0 \times 10^{5} \mathrm{Nm}^{-2}\) and density of ait is \(1.2 \mathrm{kgm}^{-3}\). For a tube of length \(1.0 \mathrm{m}\), closed at one end, the lowest frequency \(\begin{array}{lllllll}\text { generated is } & 84 & \text { Hz. } & \text { The } & \text { value } & \text { of } \boldsymbol{\gamma}\end{array}\) (ratio of two specific heats) for air isWBJEE 2016 Hard
- \(\cos \frac{2 \pi}{7}+\cos \frac{4 \pi}{7}+\cos \frac{6 \pi}{7}\)WBJEE 2014 Medium
- What will be the approximate terminal velocity of a rain drop of diameter \(1.8 \times 10^{-3} \mathrm{m}\), when density of rain water \(\approx 10^{3} \mathrm{kgm}^{-3}\) and the coefficient of viscosity of air \(\approx 1.8 \times 10^{-5} \mathrm{N}-sm^{-2}\) ? (Neglect buoyancy of air)WBJEE 2018 Easy