Answer:
0.42 m/s
Explanation:
Momentum is conserved before and after the cannon is fired. Momentum of an object (p) is equal to mass (m) times velocity (v) (speed and direction). Initially, both the cannon and the cannonball are at rest, so the total momentum of the system is zero. Therefore, the final momentum of the system must also be zero.
p = p₀
p = 0
m₁ v₁ + m₂ v₂ = 0
(850 kg) v₁ + (3 kg) (120 m/s) = 0
(850 kg) v₁ = -360 kg m/s
v₁ = -0.42 m/s
Rounded to two significant figures, the cannon recoils at 0.42 m/s.
