A projectile is launched at 60 degrees with a speed of 20 m/s. What is its vertical component of the initial velocity?

A projectile is launched at 60 degrees with a speed of 20 m/s. What is its vertical component of the initial velocity?

• A. 6.0 m/s
• B. 10.0 m/s
• C. 17.3 m/s
• D. 20.0 m/s

Answer: (C)

When a velocity is given at an angle above the horizontal, its initial speed splits into a vertical and a horizontal component. The vertical component is found by v_y0 = v sin(theta) because the vertical part corresponds to the opposite side of the velocity triangle. Here, v = 20 m/s and theta = 60°. Since sin 60° = √3/2 ≈ 0.866, the vertical component is 20 × 0.866 ≈ 17.3 m/s. So the vertical component of the initial velocity is about 17.3 m/s. (The horizontal component would be v_x0 = v cos(theta) = 20 × cos60° = 10 m/s, but that isn’t what's being asked.)

When a velocity is given at an angle above the horizontal, its initial speed splits into a vertical and a horizontal component. The vertical component is found by v_y0 = v sin(theta) because the vertical part corresponds to the opposite side of the velocity triangle.

Here, v = 20 m/s and theta = 60°. Since sin 60° = √3/2 ≈ 0.866, the vertical component is 20 × 0.866 ≈ 17.3 m/s. So the vertical component of the initial velocity is about 17.3 m/s.

(The horizontal component would be v_x0 = v cos(theta) = 20 × cos60° = 10 m/s, but that isn’t what's being asked.)