The safe allowable tension in a V-belt is 3,8 MPa and its cross-sectional area is 800 mm². What is the maximum tension to which the belt can be subjected?

The safe allowable tension (stress) ($\sigma$) is given as $3.8 \text{ MPa}$.
The cross-sectional area ($A$) is given as $800 \text{ mm}^2$.
The relationship between stress, force (tension), and area is:

where $F$ is the force or tension.

$1 \text{ MPa} = 1 \frac{\text{N}}{\text{mm}^2}$.
So, $\sigma = 3.8 \frac{\text{N}}{\text{mm}^2}$.

The maximum tension to which the belt can be subjected is $\text{3040 N}$.