Question

A 7.5 kg cannon ball leaves a canon with a speed of 185 m/s. Find the average net force applied to the ball if the cannon muzzle is 3.6 m long.

Answer 1

We would like to know the average net force. Therefore, we can calculate the acceleration using:

x = 0.5*a*t^2

v = a*t

where x=3.6m and v=185 m/s.

Therefore,

t=v/a     and hence    x = 0.5*a*(v/a)^2 = 0.5 * (v^2)/a

so    a= (0.5*v^2)/x

Since we know the values for v and x, as written above, we can calculate a by plugging the numbers in.

The average net force will then be:

F = m*a,

where m=7.5kg.