JEE Mains · Physics · STD 11 - 5. work,energy,power and collision
A block is fastened to a horizontal spring. The block is pulled to a distance \(x =10\,cm\) from its equilibrium position (at \(x =0\) ) on a frictionless surface from rest. The energy of the block at \(x =5\) \(cm\) is \(0.25\,J\). The spring constant of the spring is \(.........Nm ^{-1}\)
- A \(65\)
- B \(66\)
- C \(69\)
- D \(50\)
Answer & Solution
Correct Answer
(D) \(50\)
Step-by-step Solution
Detailed explanation
\(U _{ i } =\frac{1}{2} kx _0^2\) \(K _{ i } =0\) \(U _{ f }=\frac{1}{2} k \left(\frac{ x _0}{2}\right)^2\) \(K _{ f }=0.25\,J\) \(\frac{1}{2} kx _0^2+0=\frac{1}{2} k \frac{ x _0^2}{4}+0.25\) \(\frac{1}{2} k x _0^2 \frac{3}{4}=\frac{1}{4}\)…
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
- Which of the following statement is not true about stopping potential \(\left(\mathrm{V}_0\right)\)?JEE Mains 2024 Hard
- Two loudspeakers ( \(L_1\) and \(L_2\) ) are placed with a separation of 10 m , as shown in figure. Both speakers are fed with an audio input signal of same frequency with constant volume. A voice recorder, initially at point \(A\), at equidistance to both loud speakers, is moved by 25 m along the line \(A B\) while monitoring the audio signal. The measured signal was found to undergo 10 cycles of minima and maxima during the movement. The frequency of the input signal is __________ Hz
(Speed of sound in air is \(324 m / s\) and \(\sqrt{5}=2.23\) )
JEE Mains 2026 Hard - The current in a conductor is expressed as \(I=3 t^2+4 t^3\), where \(I\) is in Ampere and \(t\) is in second. The amount of electric charge that flows through a section of the conductor during \(t=1\) s to \(t=2 \mathrm{~s}\) is _______ \(\mathrm{C}\).JEE Mains 2024 Hard
- A galvanometer having a coil of resistance \(30 \Omega\) need 20 mA of current for full-scale deflection. If a maximum current of 3 A is to be measured using this galvanometer, the resistance of the shunt to be added to the galvanometer should be \(\frac{30}{X} \Omega\), where \(X\) is ________.JEE Mains 2025 Medium
- A long conducting wire having a current \(I\) flowing through it, is bent into a circular coil of \(N\) turns.Then it is bent into a circular coil of \(n\) tums. The magnetic field is calculated at the centre of coils in both the cases. The ratio of the magnetic field in first case to that of second case is:JEE Mains 2023 Medium
- In connection with the circuit drawn below, the value of current flowing through \(2\, k \Omega\) resistor is ............. \(\times 10^{-4} A\)
JEE Mains 2021 Medium
More PYQs from JEE Mains
- If \(X = \{ {4^n} - 3n - 1:n \in N\} \) and \(Y = \{ 9(n - 1):n \in N\} ,\) then \(X \cup Y\) = . . . . .JEE Mains 2014 Medium
- When a ball is dropped into a lake from a height \(4.9 \,m\) above the water level, it hits the water with a velocity \(v\) and then sinks to the bottom with the constant velocity \(v\). It reaches the bottom of the lake \(4.0,s\) after it is dropped. The approximate depth of the lake is ............ \(m\)JEE Mains 2022 Medium
- A monochromatic light is incident at a certain angle on an equilateral triangular prism and suffers minimum deviation. If the refractive index of the material of the prism is \(\sqrt 3\) , then the angle of incidence....\(^o\)JEE Mains 2019 Medium
- There are \(5\) points \(\mathrm{P}_1, \mathrm{P}_2, \mathrm{P}_3, \mathrm{P}_4, \mathrm{P}_5\) on the side \(\mathrm{AB}\), excluding \(\mathrm{A}\) and \(\mathrm{B}\), of a triangle \(\mathrm{ABC}\). Similarly there are \(6\) points \(\mathrm{P}_6, \mathrm{P}_7, \ldots, \mathrm{P}_{11}\) on the side \(\mathrm{BC}\) and \(7\) points \(\mathrm{P}_{12}, \mathrm{P}_{13}, \ldots, \mathrm{P}_{18}\) on the side \(\mathrm{CA}\) of the triangle. The number of triangles, that can be formed using the points \(\mathrm{P}_1, \mathrm{P}_2, \ldots, \mathrm{P}_{18}\) as vertices, is :JEE Mains 2024 Medium
- If \(\mathrm{z}\) is a complex number, then the number of common roots of the equation \(z^{1985}+z^{100}+1=0\) and \(z^3+2 z^2+2 z+1=0\), is equal to :JEE Mains 2024 Hard
- A group of students comprises of \(5\) boys and \(n\) girls. If the number of ways, in which a team of \(3\) students can randomly be selected from this group such that there is at least one boy and at least one girl in each team, is \(1750\), then \(n\) is equal toJEE Mains 2019 Hard