JEE Mains · Physics · STD 11 - Motion in straight line
- JEE Mains 2021
- Hard
- MCQ
The relation between time \(t\) and distance \(x\) for a moving body is given as \(t=m x^{2}+n x\), where \({m}\) and \({n}\) are constants. The retardation of the motion is - (Where \(v\) stands for velocity)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(2 {mv}^{3}\)
Step-by-step Solution
Detailed explanation
\(t =m x^{2}+n x\)
\(\frac{1}{v}=\frac{d t}{d x}=2 m x+n\)
\(v=\frac{1}{2 m x+n}\)
\(\frac{d v}{d t}=-\frac{2 m}{(2 m x+n)^{2}}\left(\frac{d x}{d t}\right)\)
\(a=-(2 m) v^{3}\)
More questions from Physics
- In an experiment a sphere of aluminium of mass \(0.20\, kg\) is heated upto \(150\,^oC\). Immediately, it is put into water of volume \(150\, cc\) at \(27\,^oC\) kept in a calorimeter of water equivalent to \(0.025\, kg\). Final temperature of the system is \(40\,^oC\). The specific heat of aluminium is ............ \(J/kg\,-\,^oC\) (take \(4.2\, Joule= 1\, calorie\))JEE Mains 2017 Hard
- The deflection in moving coil galvanometer falls from \(25\) divisions to \(5\) division when a shunt of \(24\ \Omega\) is applied. The resistance of galvanometer coil will be :JEE Mains 2024 Hard
- Potential energy as a function of \(r\) is given by \(U=\frac{ A }{ r ^{10}}-\frac{ B }{ r ^{5}}\), where \(r\) is the interatomic distance, \(A \) and \(B\) are positive constants. The equilibrium distance between the two atoms will beJEE Mains 2022 Medium
- A spherically symmetric charge distribution is considered with charge density varying as \(\rho(r)=\left\{\begin{array}{ll}\rho_{0}\left(\frac{3}{4}-\frac{r}{R}\right) & \text { for } r \leq R \\ \text { Zero } & \text { for } r>R\end{array}\right.\) Where, \(r ( r < R )\) is the distance from the centre \(O\) (as shown in figure). The electric field at point \(P\) will be.
JEE Mains 2022 Hard - The amount of work done to break a big water drop of radius ' \(R\) ' into 27 small drops of equal radius is 10 J . The work done required to break the same big drop into 64 small drops of equal radius will beJEE Mains 2025 Medium
- Magnetic materials used for making permanent magnets \((P)\) and magnets in a transformer \((T)\) have different properties of the following, which property best matches for the type of magnet required \(?\)JEE Mains 2020 Medium
More PYQs from JEE Mains
- Certain galvanometers have a fixed core made of non magnetic metallic material. The function of this metallic material isJEE Mains 2023 Easy
- A ball projected from ground at an angle of \(45^o\) just clears a wall in front. If point of projection is \(4\,m\) from the foot of wall and ball strikes the ground at a distance of \(6\,m\) on the other side of the wall, the height of the walI is ........ \( m\)JEE Mains 2013 Hard