Final answer:
The hang glider's resultant velocity after being hit by a gust of wind is 30 m/s downward, calculated by subtracting the wind's velocity from the glider's initial velocity since they are in opposite directions.
Step-by-step explanation:
The question involves calculating the resultant velocity of a hang glider after being affected by a gust of wind. In this scenario, the glider initially has a velocity of 40 m/s downwards, and then a gust of wind with a velocity of 10 m/s upwards hits it.
To find the resultant velocity, we subtract the wind's velocity from the glider's initial velocity because they are in opposite directions. The calculation is as follows:
Resultant velocity = Initial velocity of glider - velocity of wind = 40 m/s down - 10 m/s up = 30 m/s down.
Therefore, the hang glider's resultant velocity after the wind gust is 30 m/s downward.