Question

If I throw a baseball with a speed that's so high that γ = 2, its mass relative to the ground isA) = 2 x m(baseball)B) = (1/2) x m(baseballC) = m(baseball)

Answer 1

Let the rest mass of the baseball be m.

The Lorentz factor is given as,

$\gamma=\frac{1}{\sqrt[]{1-\frac{v^2}{c^2}}}\ldots(1)$

Here, v is the velocity of the object, and c is the speed of light.

The relative mass is given as,

$m_{rel}=\frac{m}{\sqrt[]{1-\frac{v^2}{c^2}}}$

Using equation (1),

$m_{rel}=\gamma m$

Substitute 2 for γ,

$m_{rel}=2m$

Therefore, the mass of the baseball relative to the ground is 2×m(baseball). Hence, option (A) is the correct choice.