Oliver and Lewis take part in running competitions. Oliver's mass is half the mass of Lewis, and Oliver's speed is 2 times greater than that of Lewis. By how much must Lewis speed up if he wants to have the same kinetic energy as Oliver? Lewis's original speed is 6 m/s. Give your answer to 2 decimal places if needed.
a) 2.00 m/s
b) 3.46 m/s
c) 4.00 m/s
d) 6.93 m/s