A bullet has been shot from a moving car

[Akash47]

Homework Statement

A man in a car moving with a speed $20~ms^{-1}$ shoots a bullet forward with a speed of $150~ms^{-1}$. The bullet hits a wall and stops. Find the rise in the temperature of the bullet if its specific heat is $500~Jkg^{-1}K^{-1}$.

Homework Equations

$K.E=1/2~mv^2$ and the amount of heat $Q=mSΔθ$

The Attempt at a Solution

If the real velocity of the bullet can be fined,then the problem will become very easy.I think, as the bullet was moving with the same velocity,so the velocity of the bullet with respect to the wall will be the addition of the velocity of the car and the velocity of the bullet with respect to the car.I want to know whether I am right or not.

 

[BvU]

the velocity of the bullet with respect to the wall will be the addition of the velocity of the car and the velocity of the bullet with respect to the car

Is right