JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A particle of mass \(\mathrm{m}\) is dropped from a height \(h\) above the ground. At the same time another particle of the same mass is thrown vertically upwards from the ground with a speed of \(\sqrt{2 \mathrm{gh}} .\) If they collide head-on completely inelastically, the time taken for the combined mass to reach the ground, in units of \(\sqrt{\frac{\mathrm{h}}{\mathrm{g}}}\) is
- A \({\frac{1}{2}}\)
- B \(\sqrt{\frac{1}{2}}\)
- C \(\sqrt{\frac{3}{4}}\)
- D \(\sqrt{\frac{3}{2}}\)
Answer & Solution
Correct Answer
(D) \(\sqrt{\frac{3}{2}}\)
Step-by-step Solution
Detailed explanation
Particles will collide after time \(\mathrm{t}_{0}=\frac{\mathrm{h}}{\sqrt{2 \mathrm{gh}}}\) at collision, \(\mathrm{v}_{\mathrm{A}}=\mathrm{gt}_{0} \quad \mathrm{v}_{\mathrm{B}}=\mathrm{u}_{\mathrm{B}}-\mathrm{gt}_{0}\)…
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
- A current of \(2\,A\) flows through a wire of crosssectional area \(25.0\,mm ^2\). The number of free electrons in a cubic meter are \(2.0 \times 10^{28}\). The drift velocity of the electrons is \(...............\times 10^{-6}\,ms ^{-1}\) (given, charge on electron \(=1.6 \times 10^{-19}\,C\) )JEE Mains 2023 Easy
- The dimension of mutual inductance is ............JEE Mains 2022 Medium
- A solid sphere of radius \(R\) carries a charge \((Q+q)\) distributed uniformly over its volume. A very small point like piece of it of mass \(m\) gets detached from the bottom of the sphere and falls down vertically under gravity. This piece carries charge \(q.\) If it acquires a speed \(v\) when it has fallen through a vertical height \(y\) (see figure), then : (assume the remaining portion to be spherical).
JEE Mains 2020 Hard - The position vector of the centre of mass \(\vec r\, cm\) of an asymmetric uniform bar of negligible area of cross-section as shown in figure is
JEE Mains 2019 Medium - Given below are two statements : one is labelled as Assertion \(A\) and the other is labelled as Reason \(R\). Assertion \(A\): A bar magnet dropped through a metallic cylindrical pipe takes more time to come down compared to a non-magnetic bar with same geometry and mass. Reason \(R\): For the magnetic bar, Eddy currents are produced in the metallic pipe which oppose the motion of the magnetic bar. In the light of the above statements, choose the correct answer from the options given belowJEE Mains 2023 Medium
- A body of \(\mathrm{m} \mathrm{kg}\) slides from rest along the curve of vertical circle from point \(A\) to \(B\) in friction less path. The velocity of the body at \(B\) is _______. (given, \(\mathrm{R}=14 \mathrm{~m}, \mathrm{~g}=10 \mathrm{~m} / \mathrm{s}^2\) and \(\sqrt{2}=1.4\) )
JEE Mains 2024 Hard
More PYQs from JEE Mains
- \(\mathop {\lim }\limits_{x \to \pi /4} \frac{{{{\cot }^3}\,x - \tan \,x}}{{\cos \left( {x + \pi /4} \right)}}\) isJEE Mains 2019 Hard
- A \(25\,cm\) long solenoid has radius \(2\,cm\) and \(500\) total number of turns. It carries a current of \(15\,A.\) If it is equivalent to a magnet of the same size and magnetization \(\vec M\) ( magnetic moment/ volume), then \(\left| {\vec M} \right|\) isJEE Mains 2015 Medium
- A body of mass \(\mathrm{m}=10\; \mathrm{kg}\) is attached to one end of a wire of length \(0.3\; \mathrm{m} .\) The maximum angular speed (in \(rad \;s^{-1}\) ) with which it can be rotated about its other end in space station is (Breaking stress of wire \(=4.8 \times 10^{7} \;\mathrm{Nm}^{-2}\) and area of cross-section of the wire \(=10^{-2}\; \mathrm{cm}^{2}\) ) isJEE Mains 2020 Hard
- The angle between the lines whose direction cosines satisfy the equations \(l + m + n = 0\) and \({l^2} = {m^2} + {n^2}\) isJEE Mains 2014 Medium
- Let a triangle \(A B C\) be inscribed in the circle \(x ^{2}-\) \(\sqrt{2}(x+y)+y^{2}=0\) such that \(\angle B A C=\frac{\pi}{2}\). If the length of side \(A B\) is \(\sqrt{2}\), then the area of the \(\triangle ABC\) is equal toJEE Mains 2022 Medium
- Starting from the origin at time \(t=0,\) with initial velocity \(5 \hat{ j }\, ms ^{-1},\) a particle moves in the \(x-y\) plane with a constant acceleration of \((10 \hat{ i }+4 \hat{ j })\, ms ^{-2}\). At time \(t\), its coordinates are \(\left(20\, m , y _{0}\, m \right) .\) The values of \(t\) and \(y _{0},\) are respectivelyJEE Mains 2020 Medium