A projectile is projected from the origin and passes through the point P(20 m, 10 m). At P its velocity is purely horizontal. It later returns to the horizontal level of projection. Neglect air resistance. The horizontal range of the projectile is:
Options

Question

A projectile is projected from the origin and passes through the point P(20 m, 10 m). At P its velocity is purely horizontal. It later returns to the horizontal level of projection. Neglect air resistance. The horizontal range of the projectile is:

Options

G1 Physics · Accepted Answer

Since the velocity at P is purely horizontal, P is the highest point of the trajectory. For a projectile that starts and lands at the same level, the highest point occurs at half the horizontal range. Here x at the highest point is 20 m, so R/2 = 20 ⇒ R = 40 m. Therefore option C is correct.