A mechanical engineer launched an arrow with a speed of 800.0 m/s at an angle of 75.0 degree to the horizontal . If it landed on a target 450.0 m away at the same height from which it was fired , for how long was the arrow in the air ?

Respuesta :

Answer: 2.17 s

Explanation:

The described situation is related to projectile motion (also known as parabolic motion). So, this kind of motion has a vertical component and a horizontal component; however, in this case we will only need the equation related to the horizontal displacement [tex]x[/tex]:

[tex]x=V_{o}cos \theta t[/tex]

Where:

[tex]x=45 m[/tex] is the arrow's horizontal displacement

[tex]V_{o}=800 m/s[/tex] is the arrow's initial velocity

[tex]\theta=75\°[/tex] is the angle

[tex]t[/tex] is the time the arrow is in the air

Isolating [tex]t[/tex]:

[tex]t=\frac{x}{V_{o}cos \theta}[/tex]

Solving with the given data:

[tex]t=\frac{45 m}{800 m/s cos(75\°)}[/tex]

[tex]t=2.17 s[/tex] This is the time the arrow is in the air