Question

At what speed must a 0.6 kg stone be thrown in order that it has a relativistic mass of 0.76 kg? (c = 3.00 x 10^8 m/s) (A) 0.39 c (B) 0.2847 c (C) 0.6138 c (D) 0.351c (E) 0.69768 c

Answer 1

Explanation:

It is given that,

Relativistic Mass of the stone, m₀ = 0.6

Mass, $m=0.76\ kg$

Relativistic mass is given by :

$m=\dfrac{m_o}{\sqrt{1-\dfrac{v^2}{c^2}}}$.........(1)

Where

c is the speed of light

On rearranging equation (1) we get :

$v^2=c^2(1-(\dfrac{m_o}{m})^2)$

$v=c\sqrt{ (1-(\dfrac{m_o}{m})^2)}$

$v=c\sqrt{ (1-(\dfrac{0.6}{0.76})^2)}$

v = 0.61378 c

or

v = 0.6138 c

So, the correct option is (c). Hence, this is the required solution.