Physics

1. Given:

The bullet can penetrate one board at speed .

The resistance of the board remains constant.

 

2. Understanding the Work-Energy Principle:

The kinetic energy of the bullet is used to overcome the work done by the resistance of the board. The kinetic energy of the bullet is given by:

 

Where:

is the mass of the bullet.

is the speed of the bullet.

 

The work done by the resistance is equal to the force of the resistance multiplied by the distance the bullet travels while penetrating the board:

 

Since the bullet can just penetrate one board at speed , the kinetic energy at this speed is equal to the work done to penetrate the boar...