Final answer:
The effective velocity of an airplane flying at 500 mph that encounters a 50 mph headwind is 450 mph, as you subtract the wind speed from the airplane's speed.
Step-by-step explanation:
The question is asking about the effective velocity of an airplane, taking into account a headwind that opposes its direction of motion. When an airplane encounters a headwind, its groundspeed is reduced by the speed of the wind. So, if an airplane flies at a speed of 500 mph and encounters a 50 mph headwind, you would subtract the wind speed from the airplane's speed to find the effective velocity.
The effective velocity is calculated by taking the speed of the airplane (500 mph) and subtracting the speed of the headwind (50 mph), which gives us:
500 mph - 50 mph = 450 mph
Therefore, the effective velocity of the airplane in the presence of a 50 mph headwind is 450 mph, which corresponds to answer choice b).