In real projectile motion, an object experiences three forces: gravity, drag, and lift. These are depicted in the picture above. Given this information, how would lift affect the speed of a projectile?
A) It would increase speed.
B) It would decrease speed.
C) Its effect would vary throughout the flight of the object.
D) It would have no effect.
A) It would increase speed.
B) It would decrease speed.
C) Its effect would vary throughout the flight of the object.
D) It would have no effect.
Because the lift force is perpendicular to the velocity of the object, lift can have no effect on the magnitude of velocity. The magnitude of velocity is also known as speed, so $\mathrm{(D)}$ is correct.