Answer to Question #277356 in Physics for shefatuzzaman

Question

5.0-g bullet traveling at a speed of 300 m/s enters a tree and exits the other side with a speed of 150 m/s. Where did the bullet’s lost kinetic energy go, and how much energy was transferred?

Answer 1

How much energy was transferred:

$$\Delta E=E_2-E_1=\frac12m(v_2^2-v_1^2)=-169\text{ J}.$$

169 K of of energy were lost to heat, to destroy the tree, and to overcome friction.