Question

an arrow is fired with at an angle of 50 degrees with an initial velocity of 300 m/s. It travelled 900 meters before hitting the ground. How long is the bullet in the air?

Answer 1

$$x=v_0tcos\theta,$$ $$t=\dfrac{x}{v_0cos\theta}=\dfrac{900\ m}{300\ \dfrac{m}{s}\cdot cos50^{\circ}}=4.67\ s.$$