The characteristic that will be affected by increasing the speed of an object from 30 meters per second (m/s) to 40 meters per second (m/s) is kinetic energy.
Kinetic energy is calculated using the formula:
\[ \text{Kinetic Energy} (KE) = \frac{1}{2} mv^2 \]
where \( m \) is the mass of the object and \( v \) is its speed. Since the speed is increasing, the kinetic energy will also increase.