Question:
A body of mass $05\, kg$ travels on straight line path with velocity $v=\left(3 x^2+4\right) m / s$ The net workdone by the force during its displacement from $x =0$ to $x =2 \,m$ is :
A body of mass $05\, kg$ travels on straight line path with velocity $v=\left(3 x^2+4\right) m / s$ The net workdone by the force during its displacement from $x =0$ to $x =2 \,m$ is :
Updated On: Feb 2, 2026
- 64 J
- 60 J
- 120 J
- 128 J
Hide Solution
Verified By Collegedunia
The Correct Option is B
Solution and Explanation
The correct option is (B) : 60 J
vi = 3(0)2 + 4 = 4 ≅ x = 0
vF = 3(2)2 + 4 = 16 ≅ x = 2
\(W=ΔK=\frac{1}{2}m(16^2-4^2)\)
\(=\frac{1}{2}\times\frac{1}{2}(256-16)=\frac{240}{4}\)
\(=60\ J\)
Was this answer helpful?
0
1
Top Questions on work, energy and power
- Given below are two statements:
Statement I: An object moves from position \( \vec{r}_1 \) to position \( \vec{r}_2 \) under a conservative force field \( \vec{F} \). The work done by the force is \[ W = -\int_{\vec{r}_1}^{\vec{r}_2} \vec{F} \cdot d\vec{r}. \]
Statement II: Any object moving from one location to another location can follow infinite number of paths. Therefore, the amount of work done by the object changes with the path it follows for a conservative force.
In the light of the above statements, choose the correct answer from the options given below:- JEE Main - 2026
- Physics
- work, energy and power
- Two masses \(m\) and \(2m\) are connected by a light string going over a pulley (disc) of mass \(30m\) with radius \(r=0.1\,\text{m}\). The pulley is mounted in a vertical plane and is free to rotate about its axis. The \(2m\) mass is released from rest and its speed when it has descended through a height of \(3.6\,\text{m}\) is ____________ m/s. (Assume string does not slip and \(g=10\,\text{m s}^{-2}\)).
- JEE Main - 2026
- Physics
- work, energy and power
- A large drum having radius $R$ is spinning around its axis with angular velocity $\omega$, as shown in figure. The minimum value of $\omega$ so that a body of mass $M$ remains stuck to the inner wall of the drum, taking the coefficient of friction between the drum surface and mass $M$ as $\mu$, is :
- JEE Main - 2026
- Physics
- work, energy and power
Potential energy (V) versus distance (x) is given by the graph. Rank various regions as per the magnitudes of the force (F) acting on a particle from high to low.
- JEE Main - 2026
- Physics
- work, energy and power
- A body of mass 4 kg is placed on a plane at a point P having coordinate $(3,4)$ m. Under the action of force $\vec{F} = (2\hat{i} + 3\hat{j})$ N, it moves to a new point Q having coordinates $(6,10)$ m in 4 sec. The average power and instantaneous power at the end of 4 sec are in the ratio of:
- JEE Main - 2026
- Physics
- work, energy and power
View More Questions
Questions Asked in JEE Main exam
- The time period of a simple harmonic oscillator is \[ T=2\pi\sqrt{\frac{m}{k}}. \] Measured value of mass \(m\) has an accuracy of \(10%\) and time for 50 oscillations of the spring is found to be \(60\,\text{s}\) using a watch of 2 s resolution. Percentage error in determination of spring constant \(k\) is:
- JEE Main - 2026
- Waves and Oscillations
A wire of uniform resistance \(\lambda\) \(\Omega\)/m is bent into a circle of radius r and another piece of wire with length 2r is connected between points A and B (ACB) as shown in figure. The equivalent resistance between points A and B is_______ \(\Omega\).
- JEE Main - 2026
- mechanical properties of solids
- Let $a_1,a_2,a_3,a_4$ be an A.P. of four terms such that each term of the A.P. and its common difference are integers. If $a_1+a_2+a_3+a_4=48$ and $a_1^2a_2a_3a_4+1^4=361$, then the largest term of the A.P. is equal to
- JEE Main - 2026
- Arithmetic Progression
The correct sequence of reagents for the above conversion of X to Y is :- JEE Main - 2026
- Periodic Table
- If \(x^2+x+1=0\), then the value of \(\left(x + \frac{1}{x}\right)^2 + \left(x^2 + \frac{1}{x^2}\right)^2 + \left(x^3 + \frac{1}{x^3}\right)^2 + \dots + \left(x^{25} + \frac{1}{x^{25}}\right)^2\) is:
- JEE Main - 2026
- Complex numbers
View More Questions
Concepts Used:
Work, Energy and Power
Work:
- Work is correlated to force and the displacement over which it acts. When an object is replaced parallel to the force's line of action, it is thought to be doing work. It is a force-driven action that includes movement in the force's direction.
- The work done by the force is described to be the product of the elements of the force in the direction of the displacement and the magnitude of this displacement.
Energy:
- A body's energy is its potential to do tasks. Anything that has the capability to work is said to have energy. The unit of energy is the same as the unit of work, i.e., the Joule.
- There are two types of mechanical energy such as; Kinetic and potential energy.
Read More: Work and Energy
Power:
- Power is the rate at which energy is transferred, conveyed, or converted or the rate of doing work. Technologically, it is the amount of work done per unit of time. The SI unit of power is Watt (W) which is joules per second (J/s). Sometimes the power of motor vehicles and other machines is demonstrated in terms of Horsepower (hp), which is roughly equal to 745.7 watts.
- Power is a scalar quantity, which gives us a quantity or amount of energy consumed per unit of time but with no manifestation of direction.