Work Power And Energy Ques 1
1 A particle moves in one dimension from rest under the influence of a force that varies with the distance travelled by the particle as shown in the figure. The kinetic energy of the particle after it has travelled $3 \mathrm{~m}$ is
(2019 Main, 08 April I)
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Answer:
Correct Answer: 1.( c )
Solution:
Formula:
$\therefore$ Work done on the particle $=$ Area under the curve $A B C$ $W=$ Area of square $A B F O+$ Area of $\triangle B C D$
- Area of rectangle $B D E F$
$ =2 \times 2+\frac{1}{2} \times 1 \times 1+2 \times 1=6.5 \mathrm{~J} $
Now, from work-energy theorem,
$ \begin{aligned} & \Delta W=K_f-K_i \\ & \Rightarrow \quad K_f=\Delta W=6.5 \mathrm{~J} \quad\left[\because K_i=0\right] \\ & \end{aligned} $
BETA
