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) 0.69768c B) 0.6138 c C) 0.33 c D) 0.2409 c E) 0.415 c

Answer 1

Answer:

The speed of the stone is 0.6138 c.

(B) is correct option.

Explanation:

Given that,

Mass of stone m= 0.6

Relativistic mass = 0.76

We need to calculate the speed

Using formula of rest mass

$m_{r}=\dfrac{m_{0}}{\sqrt{1-\dfrac{v^2}{c^2}}}$

$v^2=(\dfrac{m_{0}^2}{m_{r}^2}-1)c^2$

Put the value into the formula

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

$v=\sqrt{0.37673c^2}$

$v=0.6138c$

Hence, The speed of the stone is 0.6138 c.