Question

The trajectory of a projectile near the surface of the earth is given as y = 2x – 9x². If it were launched at an angle 0₀ with speed v₀ then (g = 10 ms⁻²) :
(A) θ₀ = cos⁻¹(1/√5) and v₀ = 5/3 ms⁻¹
(B) θ₀ = cos⁻¹(2/√5) and v₀ = 3/5 ms⁻¹
(C) θ₀ = sin⁻¹(1/√5) and v₀ = 3/5 ms⁻¹
(D) θ₀ = sin⁻¹(1/√5) and v₀ = 5/3 ms⁻¹

Answer 1

The trajectory of a projectile near the surface of the earth is given as y = 2x – 9x². If it were launched at an angle 0₀ with speed v₀ then (g = 10 ms⁻²) :

(A) θ₀ = cos⁻¹(1/√5) and v₀ = 5/3 ms⁻¹✓✓

(B) θ₀ = cos⁻¹(2/√5) and v₀ = 3/5 ms⁻¹

(C) θ₀ = sin⁻¹(1/√5) and v₀ = 3/5 ms⁻¹

(D) θ₀ = sin⁻¹(1/√5) and v₀ = 5/3 ms⁻¹