Question:
The velocity-time graph for a body of mass \( 10\,\text{kg} \) is shown. Work done on the body in the first two seconds of motion is
The velocity-time graph for a body of mass \( 10\,\text{kg} \) is shown. Work done on the body in the first two seconds of motion is
Show Hint
Work-energy:
Use KE change when velocity known.
Use KE change when velocity known.
Updated On: Mar 2, 2026
- \( -9300\,\text{J} \)
- \( 12000\,\text{J} \)
- \( -4500\,\text{J} \)
- \( -12000\,\text{J} \)
Show Solution
Verified By Collegedunia
The Correct Option is C
Solution and Explanation
Concept:
Work done = change in kinetic energy:
\[
W = \frac12 m(v^2 - u^2)
\]
Step 1: {\color{red}From graph.}
Velocity decreases linearly from \( 50\,\text{m/s} \) to 0 in 10 s.
Slope:
\[
a = -5\,\text{m/s}^2
\]
Step 2: {\color{red}Velocity at 2 s.}
\[
v = 50 - 5\times2 = 40\,\text{m/s}
\]
Step 3: {\color{red}Work done.}
\[
W = \frac12 \cdot 10 (40^2 - 50^2)
\]
\[
W = 5(1600 - 2500) = -4500\,\text{J}
\]
Was this answer helpful?
0
0
Top WBJEE Physics Questions
- The velocity of a particle executing a simple harmonic motion is $13\, ms^{-1}$, when its distance from the equilibrium position (Q) is 3 m and its velocity is $12 \, ms^{-1}$, when it is 5 m away from The frequency of the simple harmonic motion is
- A and B are two parallel sided transparent slabs of refractive indices n$_1 $and n$_2$ respectively. A ray is incident at an angle $\theta$ on the surface of separation of A and B, and after refraction from B into air grazes the surface of B. Then
- The minimum and maximum capacitances, which may be obtained by the combination of three capacitors each of capacitance 6$\mu$ F are
- The increase in electrostatic potential energy of a dipole of moment p when it is taken from parallel to anti-parallel orientation in an electric field E is
- A zener diode has break down voltage of 5.0 V. The resistance required to allow a current of 100 mA through the zener in reverse bias when connected to a battery of emf 12 V is
View More Questions
Top WBJEE Work Power Energy Questions
- A small sphere of mass m and radius R slides down the smooth surface of a large hemispherical bowl of radius R. If the sphere starts sliding from rest, the total kinetic energy of the sphere at the lowest point A of the bowl will be:
- The following figure shows the variation of potential energy V (x) of a particle with distance x. The particle has:
Top WBJEE Questions
- Let $\vec{\alpha } = \hat{i} + \hat{j} + \hat{k} , \vec{\beta} = \hat{i} - \hat{j} - \hat{k}$ and $\vec{\gamma} = - \hat{i} + \hat{j} - \hat{k}$ be three vectors. A vector $\vec{\delta} $, in the plane of $\vec{\alpha}$ and $\vec{\beta}$, whose projection on $\vec{\gamma}$ is $\frac{1}{\sqrt{3}}$, is given by
- Let a, b, c be real numbers such that $a + b + c < 0$ and the quadratic equation $ax^2 + bx + c = 0$ has imaginary roots. Then
- If the radius of a spherical balloon increases by 0.1%, then its volume increases approximately by
- The velocity of a particle executing a simple harmonic motion is $13\, ms^{-1}$, when its distance from the equilibrium position (Q) is 3 m and its velocity is $12 \, ms^{-1}$, when it is 5 m away from The frequency of the simple harmonic motion is
- By which of the following methods, new and better varieties of plants can be formed?
View More Questions