Without air resistance, a projectile fired horizontally at 8 km/s from atop a mountain will
A)accelerate downward at g as it moves horizontally.
B)trace a curve that matches Earth's curvature.
C)return later to its starting position and repeat its falling behavior.
D)all of the above
E)none of the above

Question

Quizplus · Accepted Answer

All of the statements are correct. A projectile fired horizontally in the absence of air resistance will accelerate downward at the acceleration due to gravity (g), trace a curve that matches Earth's curvature because its horizontal speed is sufficient to fall around the Earth rather than into it, and it will theoretically return to its starting position if it maintains that speed without encountering resistance, thus repeating its trajectory.

Without Air Resistance, a Projectile Fired Horizontally at 8 Km/s