Question

Which of the following Statements is accurate for an object approaching the speed of light?
A) The particles mass will increase as it approaches the speed of light
B) The particle mass will increase as it approaches and then decreases when it reaches the speed of light
C) The particle mass will decrease as it approaches the speed of light
D) The particle dimensions will increase but its mass will remain constant at it approaches the speed of light
E) All of the statements are accurate.

Answer 1

Hint: By the theory of relativity and planck's theory it is possible that if a body increases its speed to approach the speed of light then its mass increases, the mass of the body becomes inversely proportional to its speed.

Complete step by step answer:
 By the theory of relativity, we have a formula or relation between mass at rest and mass of a moving body and its speed.
i.e. $m = \dfrac{{{m_o}}}{{\sqrt {1 - {{\left( {\dfrac{v}{c}} \right)}^2}} }}$
Where, $m$ is the mass of the moving body, ${m_0}$ is the mass of body at rest, $v$ is the speed by which body is moving and $c$ is speed of light i.e. $3 \times {10^8}m/\sec $
So, from the above formula we can conclude that if the speed of a body increases then mass of body decreases, but for a significant change in mass the velocity of a body must be comparable to light’s speed. We can see that if the mass of the body approaches the speed of light then the denominator of formula approaches zero. It means the mass of the moving body becomes infinite.
$ \Rightarrow v \to c,m \to \infty $
Hence its mass increases with increase in speed
Hence, OPTION (A) is correct.

Additional Information:
Special relativity was originally proposed by Albert Einstein in a paper published on 26 September 1905 titled "On the Electrodynamics of Moving Bodies". The incompatibility of Newtonian mechanics with Maxwell's equations of electromagnetism and, experimentally, the Michelson-Morley null result (and subsequent similar experiments) demonstrated that the historically hypothesized did not exist. This led to Einstein's development of special relativity, which corrects mechanics to handle situations involving all motions and especially those at a speed close to that of light (known as relativistic velocities). Today, special relativity is proven to be the most accurate model of motion at any speed when gravitational and quantum effects are negligible. Even so, the Newtonian model is still valid as a simple and accurate approximation at low velocities (relative to the speed of light).

Note: Modern, Quantum, or Einstein physics is too different from Classical or Newtonian physics. In Classical Physics mass can neither be created nor be destroyed but in modern physics it becomes possible by theory of relativity. For any body approaching the speed of light, the mass of the body changes. The equation of mass for the body moving with a speed comparable to light proves that nothing can travel faster than light.