#### Answer

The kinetic energy of Charles Murphy and his bicycle is $27,200~J$
The kinetic energy of John Howard and his bicycle is $1.63\times 10^5~J$

#### Work Step by Step

We can find the kinetic energy of Charles Murphy and his bicycle:
$KE = \frac{1}{2}mv^2$
$KE = \frac{1}{2}(70.5~kg)(27.8~m/s)^2$
$KE = 27,200~J$
The kinetic energy of Charles Murphy and his bicycle is $27,200~J$
We can find the kinetic energy of John Howard and his bicycle:
$KE = \frac{1}{2}mv^2$
$KE = \frac{1}{2}(70.5~kg)(68.04~m/s)^2$
$KE = 1.63\times 10^5~J$
The kinetic energy of John Howard and his bicycle is $1.63\times 10^5~J$.