Question

40) A 1.5-kg cannonball is fired out of a 30-kg cannon. The recoil speed of the cannon is measured to be 0.1 m/s
. Draw an impulse-momentum bar chart and determine the speed at which the cannonball was fired.

Answer 1

Given that:

Mass of the cannon, M = 30 kg

Mass of the cannonball, m = 1.5 kg

Initial speed of the cannon, U₂ = 0 m/s

​​​​​​​Initial speed of the cannon ball, U₁ = 0 m/s

Final speed of the cannon/recoil speed, V₂ = 0.1 m/s

Let V₁ be the final speed of the cannonball.

From law of conservation of momentum, We have:

Substituting given values:

That is the firing speed of the cannonball was 2 m/s. (the negative sign indicates that the direction of motion of cannonball was in opposite direction of the motion of the cannon)