A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by 1𝑚/𝑠 so as to have same 𝐾. 𝐸. as that of the boy. The original speed of the man will be

May 10, 2022

by Ezee_Notes

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Physics Problems

Question: A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by 1𝑚/𝑠 so as to have same 𝐾. 𝐸. as that of the boy. The original speed of the man will be

(A) $\sqrt{2}$ 𝑚/𝑠

(B) $\left( \sqrt{2}-1\right)$ 𝑚/𝑠

(D) $\dfrac{1}{\sqrt{2}}$

Answer: Option (C)

Solution:

A running man has half the kinetic energy of that of a boy of half of his mass. The man speeds up by 1𝑚/𝑠 so as to have same 𝐾. 𝐸. as that of the boy. The original speed of the man will be