CATapult!

Remember that the energy of a moving object, with some mass $m$ and some velocity $v$ , is $\frac{mv^2}{2}$ . Therefore, the energy of the cat is $\frac{9\cdot70^2}{2}$ or $\frac{9\cdot4900}{2}$ or $\frac{44100}{2}$ or $22050$ joules. Now we must use some algebra to find the velocity of the unsuspecting enemy whose mass is $63\mathrm{kg}$ (remember that the question specifies that all the energy goes into the enemy):

$22050 = \frac{63v^2}{2}$ $44100 = 63v^2$ $700 = v^2$ $\sqrt{700} = v$

Therefore, the speed at which the enemy is bowled over is $\sqrt{700}\mathrm{\frac{m}{s}}$ . This is in $\mathrm{\frac{m}{s}}$ already, so we've met the units requirement, and now we must round to the nearest hundredth to get:

$26.46$