Determining a temperature increase from heat energy 
A 15.0g bullet traveling horizontally at 865 $\frac{m}{s}$ passes through at a tank containing $13.5$kg of water and emerges with a speed of $534\frac{m}{s}$.  What is the maximum temperature increase that the water could have as a result of this event?

I started by using the following formulas:

$Q=nC\Delta T$
$C=Mc$
$m=nM$

I found $n$ by doing $\frac{13.5kg}{.0180 \frac{kg}{mol}}$ which is $750$ moles.
$C$ I found to be $(.0180 \frac{kg}{mol})(4190J) = 75.42 \frac{kgJ}{mol}$
But I'm not sure how to solve $Q=nC\Delta T$ because I don't know how to find $\Delta T$.
Am I going about this the correct way?
 A: Q is the heat gained by the water.  In this problem, the thermal energy gained by the water must come from the kinetic energy the bullet lost in the water.
Find the kinetic energy lost by the bullet, and that will give you the maximum possible heat gained by the water, Q.
A: Hint:  Loss of Kinetic Energy of the bullet = Gain in the Heat Energy of the water.
A: As the other answers say, you need formulas for kinetic energy also. Then you can find $Q$. In fact you need these two formulas:
$$(1)\:\:\:\: K=\frac{1}{2}mv^2\\ (2)\:\:\:\:-\Delta K=Q\Rightarrow -(K_{after}-K_{before})=Q$$
The loss in kinetic energy $\Delta K$ of the bullet equals the heat $Q$ to the water. This is conservation of energy (where other energy types like work and potential energy changes not are present.) There are no other places for this energy to go than as heat into the water (and into the bullet maybe, but that would be negligible).
Note, your units for heat capacity don't match.
In the formula 
$$Q=nC\Delta T$$
the heat $Q$ must be in joules $[\mathrm{J}]$. Since $n$ is in $[\mathrm{moles}]$ and a temperature difference $\Delta T$ is in $[\mathrm{K}]$, your heat capacity $C$ must have units of $\left [\mathrm{\frac{J}{mol \cdot K}} \right ]$.
Your units are $C=\left [\mathrm{\frac{kg \cdot J}{mol}} \right ]$. Looks like you inserted wrong units for the specific heat capacity $c$ in the formula $C=Mc$, which should have been $c=\left [\mathrm{\frac{J}{kg \cdot K}} \right ]$ and not $c=\left [\mathrm{J} \right ]$.
