An Electron of Mass 9

An electron of mass 9.11 × 10−³¹ kg moves with a speed of 0.800c.What is its kinetic energy? (c = 3.00 × 10⁸ m/s)

A) 5.47 × 10−¹⁴ J
B) 2.05 × 10−¹⁴ J
C) 3.90 × 10−¹⁴ J
D) 6.22 × 10−¹⁴ J