Work Energy and Power - Result Question 22

25. If the kinetic energy of a particle is increased by $300 %$, the momentum of the particle will increase by

[2002]

(a) $20 %$

(b) $200 %$

(c) $100 %$

(d) $50 %$

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Answer:

Correct Answer: 25. (c)

Solution:

  1. (c) New K.E., $E^{\prime}=E+3 E=4 E$

$p=\sqrt{2 m E}$ and $p^{\prime}=\sqrt{2 m E^{\prime}}$

$\frac{p^{\prime}}{p}=\sqrt{\frac{2 m \times 4 E}{2 m E}}=2$

$ \begin{aligned} & \frac{p^{\prime}}{p}-1=2-1 \text{ [on substrating } 1 \text{ in both sides.] } \\ & \frac{p^{\prime}-p}{p} \times 100=(2-1) \times 100=100 % \end{aligned} $