An Unknown Particle in an Accelerator Moving at a Speed

Multiple Choice

An unknown particle in an accelerator moving at a speed of 2.00 × 10⁸ m/s has a measured total energy of 1.22 × 10−⁹ J.What is its mass? (c = 3.00 × 10⁸ m/s)

A) 1.49 × 10−²⁶ kg
B) 0.650 × 10−²⁶ kg
C) 0.810 × 10−²⁶ kg
D) 1.01 × 10−²⁶ kg