JEE Mains · Physics · STD 11 - Motion in straight line
- JEE Mains 2018
- Medium
- Numerical
An automobile, travelling at \(40\, km/h\), can be stopped at a distance of \(40\, m\) by applying brakes. If the same automobile is travelling at \(80\, km/h\), the minimum stopping distance, in metres, is (assume no skidding)..........\(m\)
Pick an option to check your answer.
Answer & Solution
Correct Answer
(B) \(160\)
Step-by-step Solution
Detailed explanation
\(\begin{array}{l}
According\,to\,question,\,{u_1} = 40\,km/h,\,{v_1} = 0\\
and\,{s_1} = 40\,m\\
{\rm{using}}\,{{\rm{v}}^2} - {u^2} = 2as;\,{0^2} - {40^2} = 2a \times 40\,\,\,\,\,\,...\left( i \right)\\
Again,\,{0^2} - {80^2} = 2as\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...\left( {ii} \right)\\
From\,eqn.\left( i \right)\,and\,\left( {ii} \right)\,\\
Stopping\,{\rm{ distance}},\,s = 160\,m\,\,
\end{array}\)
According\,to\,question,\,{u_1} = 40\,km/h,\,{v_1} = 0\\
and\,{s_1} = 40\,m\\
{\rm{using}}\,{{\rm{v}}^2} - {u^2} = 2as;\,{0^2} - {40^2} = 2a \times 40\,\,\,\,\,\,...\left( i \right)\\
Again,\,{0^2} - {80^2} = 2as\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,\,...\left( {ii} \right)\\
From\,eqn.\left( i \right)\,and\,\left( {ii} \right)\,\\
Stopping\,{\rm{ distance}},\,s = 160\,m\,\,
\end{array}\)
More questions from Physics
- If the collision frequency of hydrogen molecules in a closed chamber at \(27^{\circ} \mathrm{C}\) is \(\mathrm{Z}\), then the collision frequency of the same system at \(127^{\circ} \mathrm{C}\) is _______.JEE Mains 2024 Hard
- The specific heats, \(C_P\) and \(C_V\) of a gas of diatomic molecules, \(A\), are given (in units of \(J\, mol^{-1}\, K^{-1}\)) by \(29\) and \(22\), respectively. Another gas of diatomic molecules \(B\), has the corresponding values \(30\) and \(21\). If they are treated as ideal gases, thenJEE Mains 2019 Hard
- A ball of mass \(4\, kg\), moving with a velocity of \(10\, ms ^{-1}\), collides with a spring of length \(8\, m\) and force constant \(100\, Nm ^{-1}\). The length of the compressed spring is \(x\, m\). The value of \(x\), to the nearest integer, is ........ .JEE Mains 2021 Medium
- A real gas within a closed chamber at \(27^{\circ} \mathrm{C}\) undergoes the cyclic process as shown in figure. The gas obeys \(P V^3=\mathrm{RT}\) equation for the path \(A\) to \(B\). The net work done in the complete cycle is _______.(assuming \(R=8 \mathrm{~J} / \mathrm{molK}\) )JEE Mains 2024 Hard
- The typical output characteristics curve for a transistor working in the common-emitter configuration is shown in the figure. The estimated current gain from the figure is
JEE Mains 2021 Medium - A body cools from \(60^{\circ} C\) to \(40^{\circ} C\) in \(6\) minutes. If, temperature of surroundings is \(10^{\circ} C\). Then, after the next 6 minutes, its temperature will be \(.........{ }^{\circ} C\).JEE Mains 2023 Medium
More PYQs from JEE Mains
- Moment of Inertia \((M.I.)\) of four bodies having same mass ' \(M\) ' and radius ' \(2 R^{\prime}\) are as follows \(I _{1}=\) \(M.I.\) of solid sphere about its diameter \(I _{2}=\) \(M.I.\) of solid cylinder about its axis \(I _{3}=\) \(M.I.\) of solid circular disc about its diameter \(I _{4}=\) \(M.I.\) of thin circular ring about its diameter If \(2\left(I_{2}+I_{3}\right)+I_{4}=x\). \(I_{1}\) then the value of \(x\) will be.......JEE Mains 2022 Medium
- A capillary tube of radius 0.1 mm is partly dipped in water (surface tension \(70 \mathrm{dyn} / \mathrm{cm}\) and glass water contact angle \(\simeq 0^{\circ}\)) with \(30^{\circ}\) inclined with vertical. The length of water risen in the capillary is ________ cm.
\(\left(\right.\) Take \(\left.\mathrm{g}=9.8 \mathrm{~m} / \mathrm{s}^2\right)\)JEE Mains 2025 Medium - Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason R .
Assertion A : If oxygen ion \(\left(\mathrm{O}^{-2}\right)\) and Hydrogen ion \(\left(\mathrm{H}^{+}\right)\)enter normal to the magnetic field with equal momentum, then the path of \(\mathrm{O}^{-2}\) ion has a smaller curvature than that of \(\mathrm{H}^{+}\).
Reason R : A proton with same linear momentum as an electron will form a path of smaller radius of curvature on entering a uniform magnetic field perpendicularly.
In the light of the above statements, choose the correct answer from the options given below :JEE Mains 2025 Easy