Below is a table of values of gamma. At what speed (approximately) is the kinetic energy of a particle equal to its rest mass energy?

Yellow: v=0.50c            Pink: v=0.75c            Green: v=0.87c           Blue: v=0.96c

Purple: None of these (to two place precision).

v/c

gamma

0.1

1.0050

0.5

1.155

0.6

1.250

0.7

1.400

0.8

1.667

0.9

2.29

0.95

3.20

0.99

7.09

0.999

22.4

0.9999

70.7

0.99999

223

Answer: v=0.87c. Gamma = 2