How do you find the horizontal Velocity?

A cannon is angled at 65 degrees from the ground. The projectile's initial velocity is 9m/s. Disregarding air friction, estimate the horizontal velocity of the projectile.

1 Answer
May 24, 2018

#"horizontal velocity" = 3.8 m/s#

Explanation:

Find the horizontal component of the velocity: #9 m/s " at an angle of "65^@ " above horizontal"#.

Start by drawing that velocity vector. Next draw a horizontal line out under the vector. Now drop a line straight down until it intersects your horizontal line. You have a right triangle. The length of the vertical line represents the vertical component of the initial velocity. The horizontal line is the horizontal velocity. The hypotenuse is the initial velocity.

The trig function cosine is #"adjacent"/"hypotenuse"#. Let's use it.

#cos65^@ = "horizontal velocity"/"initial velocity"#

Solve for #"horizontal velocity"#.

#"horizontal velocity" = cos65^@*9 m/s = 3.8 m/s#

I hope this helps,
Steve