A novice scuba diver practicing in a swimming pool takes enough air from his tank to fully expand his lungs before abandoning the tank at depth l. and swimming to the surface , failing to exhale during his ascent . At the surface , the difference `Delta` p between the external pressure on him and the air pressure in his lungs is 9.3 kPa . From what depth does he start ? What potentially lethal danger does he face ?

Explanation

To solve the problem, we need to determine the depth from which the scuba diver starts, given the pressure difference between the external pressure and the air pressure in his lungs at the surface.

### Step-by-Step Solution:

1. **Understanding Pressure at Depth**:
The pressure at a certain depth \( L \) in a fluid can be expressed as:
\[
P = P_{\text{atm}} + \rho g L
...