Problem: A cannon tilted up at a 26° angle fires a cannonball at 71m/s from atop a 12m -high fortress wall.What is the ball's impact speed on the ground below?

FREE Expert Solution

Uniform accelerated motion (UAM) equations:
 vf=v0-gty=(vf+v02)ty=v0t-12gt2 vf2=v02-2gy

Velocity components:

vx=|v| cos θvy=|v| sin θ

Vector magnitude:

|v|=vx2+vy2

Let the y-axis point vertically and the x-axis horizontally with the origin located at the base of the fortress:

  • vf,y = ?
  • Δy = yf - y0 = 0 - 12 = - 12 m
  • yf = 0 m
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Problem Details

A cannon tilted up at a 26° angle fires a cannonball at 71m/s from atop a 12m -high fortress wall.

What is the ball's impact speed on the ground below?

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