JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A body of mass 4 kg is placed on a plane at a point P having coordinate \((3,4) \mathrm{m}\). Under the action of force \(\overrightarrow{\mathrm{F}}=(2 \hat{i}+3 \hat{j}) \mathrm{N}\), it moves to a new point Q having coordinates \((6,10) \mathrm{m}\) in 4 sec . The average power and instanteous power at the end of 4 sec are in the ratio of :
- A \(13: 6\)
- B \(4: 3\)
- C \(1: 2\)
- D \(6: 13\)
Answer & Solution
Correct Answer
(D) \(6: 13\)
Step-by-step Solution
Detailed explanation
\begin{aligned} & \langle\mathrm{p}\rangle=\frac{(2 \hat{\mathrm{i}}+3 \hat{\mathrm{j}}) \cdot(3 \hat{\mathrm{i}}+6 \hat{\mathrm{j}})}{4}=6 \\ & \overrightarrow{\mathrm{a}}=\left(\frac{\overrightarrow{\mathrm{F}}}{\mathrm{m}}=\frac{1}{2} \hat{\mathrm{i}}+\frac{3}{4}…
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
- \(300 \,cal\). of heat is given to a heat engine and it rejects \(225 \,cal\). of heat. If source temperature is \(227^{\circ} C\), then the temperature of sink will be____\({ }^{\circ} C\).JEE Mains 2022 Medium
- If a copper wire is stretched to increase its length by \(20 \% \). The percentage increase in resistance of the wire is \(..........\%\)JEE Mains 2023 Medium
- A deuteron and a proton moving with equal kinetic energy enter into to a uniform magnetic field at right angle to the field. If \(r_{d}\) and \(r_{p}\) are the radii of their circular paths respectively, then the ratio \(\frac{r_{d}}{r_{p}}\) will be \(\sqrt{ x }: 1\) where \(x\) is ..........JEE Mains 2022 Medium
- A piece of wood from a recently cut tree shows \(20\,decays\) per minute. A wooden piece of same size placed in a museum ( obtained from a tree cut many years back) shows \(2\,decays\) per minute. If half life of \(C^{14}\) is \(5730\, years\), then age of the wooden piece placed in the museum is approximately ........... \(years\)JEE Mains 2014 Hard
- For the plane electromagnetic wave given by \(\mathrm{E}=\mathrm{E}_0 \sin (\omega \mathrm{t}-\mathrm{kx})\) and \(\mathrm{B}=\mathrm{B}_0 \sin (\omega \mathrm{t}-\mathrm{kx})\), the ratio of average electric energy density to average magnetic energy density isJEE Mains 2023 Medium
- Given below are two statements: one is labelled as Assertion A and the other is labelled as Reason \(R\). Assertion \(A:\) Alloys such as constantan and manganin are used in making standard resistance coils. Reason \(R:\) Constantan and manganin have very small value of temperature coefficient of resistance.In the light of the above statements, choose the correct answer from the options given below.JEE Mains 2022 Medium
More PYQs from JEE Mains
- If \(\int \sin ^{-1}\left(\sqrt{\frac{x}{1+x}}\right) d x=A(x) \tan ^{-1}(\sqrt{x})+B(x)+C\) where \(C\) is a constant of integration, then the ordered pair \(( A ( x ), B ( x ))\) can beJEE Mains 2020 Hard
- The general displacement of a simple harmonic oscillator is \(x = A \sin \omega t\). Let \(T\) be its time period. The slope of its potential energy (U) - time (t) curve will be maximum when \(t=\frac{T}{\beta}\). The value of \(\beta\) is \(.........\)JEE Mains 2023 Hard
- From a group of \(10\) men and \(5\) women, four member committees are to be formed each of which must contain at least one woman. Then the probability for these committees to have more women than men, isJEE Mains 2017 Hard
- As shown in the diagram, when the incident ray is parallel to base of the prism, the emergent ray grazes along the second surface.

If refractive index of the material of prism is \(\sqrt{2}\), the angle \(\theta\) of prism is.JEE Mains 2026 Medium - A capacitor C is first charged fully with potential difference of \( V_{0} \) and disconnected from the battery. The charged capacitor is connected across an inductor having inductance L. In time t, 25% of the initial energy in the capacitor is transferred to the inductor. The value of t isJEE Mains 2026 Easy
- This question has Statement-I and Statement-2. Of the four ch.oices given after the Statements, choose the one that best describes the two Statetnents. Statement \(-1\) : A capillary is dipped in a liquid and liquid rises to a height \(h\) in it. As the temperature of the liquid is raised, the height \(h\) increases (if the density of the liquid and the angle of contact remain the same). Statement \(-2\) : Surface tension of a liquid decreases with the rise in its temperature.JEE Mains 2013 Medium