find the speed of the projectile

Question

a rocket is launched at 20m/s at an angle of 50 degrees horizontally. It blows up 7 seconds after it took off. find the speed of the projectile before it blew up.

Answer 1

v_x = v₀cosθ = 20cos50° = 12.86 m/s

v_y = v₀sinθ - gt = 20sin50° - 9.8(7)m/s = -53.28 m/s

v = √(v_x² + v_y²) = √[(12.86)² + (-53.28)²] m/s = ? m/s