Variable Mass System PYQs: JEE Mains Physics

Showing 1–5 of 5 questions

1. 1. The position of an object having mass \(0.1\) kg as a function of time \(t\) is given as \(\vec{r} = \left(10t^2\hat{i} + 5t^3\hat{j}\right)\) m. At \(t = 1\) s, which of the following statements are correct?
   A. The linear momentum \(\vec{p} = \left(2\hat{i} + 1.5\hat{j}\right)\) kg·m/s.
   B. The force acting on the object \(\vec{F} = \left(2\hat{i} + 3\hat{j}\right)\) N.
   C. The angular momentum of the object about its origin \(\vec{L} = 15\hat{k}\) J·s.
   D. The torque acting on the object about its origin \(\vec{\tau} = 20\hat{k}\) N·m.
   Choose the correct answer from the options given below : 2026 Medium
2. 2. A balloon has mass of \(10\,g\) in air. The air escapes from the balloon at a uniform rate with velocity \(4.5\,cm / s\). If the balloon shrinks in \(5\,s\) completely. Then, the average force acting on that balloon will be (in dyne). 2022 Easy
3. 3. A block of metal weighing \(2 \,kg\) is resting on a frictionless plane (as shown in figure). It is struck by a jet releasing water at a rate of \(1 \,kgs ^{-1}\) and at a speed of \(10 \,ms ^{-1}\). Then, the initial acceleration of the block, in \(ms ^{-2}\), will be .................
   2022 Medium
4. 4. The initial mass of a rocket is \(1000\, {kg} .\) Calculate at what rate the fuel (In \({kg} {s}^{-1}\)) should be burnt so that the rocket is given an acceleration of \(20 \,{ms}^{-2}\). The gases come out at a relative speed of \(500\, {ms}^{-1}\) with respect to the rocket : [Use \( g = 10\, {m} / {s}^{2}\) ] 2021 Medium
5. 5. A spaceship in space sweeps stationary interplanetary dust. As a result, its mass increases at a rate \(\frac{ dM ( t )}{ dt }= bv ^{2}( t ),\) where \(v ( t )\) is its instantaneous velocity. The instantaneous acceleration of the satellite is 2020 Hard

No questions on this page match these filters. Clear filters