Question

The cannon on a pirate ships shoots cannon balls with a speed of 350m/s (the muzzle velocity). The cannon can be adjusted to shoot at any elevation above the horizontal.


If the cannon’s barrel is 2m long and the force on the cannon ball is constant, what is the acceleration of the cannon ball in m/s2 inside the barrel?

Answer 1

average velocity in the barrel is ... (0 + 350) / 2 = 175 m/s

time in the barrel is ... 2 m / 175 m/s

acceleration is ... 350 m/s / (time in barrel)

Answer 2

The previous answer is incorrect. Here's the correct solution.

The muzzle velocity is 350 m/s and the distance covered (x) is 2m.

So from the known variables,
displacement (s) = 2m.
initial velocity (u) = at rest (0 m/s).
final velocity at end of 2m (v) (before shooting) = 350 m/s.
acceleration (a) = ?
time (t) = ?

So we use the kinematics equation: v^2 = u^2 + 2as.
Rearranging the equation:

a = (v^2 - u^2) / 2s.

Now, just plug in the values to get the final answer for a in m/s.
HINT: It should be about 3zzzz m/s.

Hope this helps!!