A bullet is fired with an initial velocity of 100 m/s at an angle of 53° from the level ground. Determine the amount of time the bullet spends in the air.

(Use 10 m/s for gravity)

2 answers

*10 m/s ^2
Vertical velocity:

Vy = V₀ sin θ = 100 ∙ sin 53° = 79.8636

Height:

h = Vy ∙ t - g t² / 2

When the bullet touches the ground the height will be zero.

Vy ∙ t - g t² / 2 = 0

Add g t² / 2 to both sides

Vy ∙ t = g t² / 2

Divide both sides by t

Vy = g t / 2

Multiply both sides by 2

2 Vy = g t

2 Vy / g = t

t = 2 Vy / g

t = 2 ∙ 79.8636 / 10 = 15.97272

t ≈ 16 sec