A projectile is launched at an angle of 30° above the horizontal with an initial velocity of 40 m/s. What is the horizontal component of the projectile's velocity when it reaches its maximum height?

Core Concept

The horizontal component of velocity remains constant throughout the projectile's motion (assuming no air resistance). The horizontal component is given by vₓ = v₀ cos θ, where v₀ = 40 m/s and θ = 30°. Thus, vₓ = 40 cos 30° = 40 × (√3/2) ≈ 40 × 0.866 = 34.6 m/s. Option A is incorrect as it would only be true if the projectile were launched vertically. Option B is incorrect as it appears to be using sin 30° instead of cos 30°. Option D is incorrect as it's the initial velocity without accounting for the angle.