Answer: 83.8 m/s
Step-by-step explanation:
momentum of shell = momentum of cannon
M(s) × V(s) = M(c) × V(c)
M(s) = mass of shell, V(s) = velocity of shell
M(c) = mass of cannon, V(c) = velocity of cannon
100kg × 75m/s = 90kg × V(c)
7500 = 90 × V(c)
7500 ÷ 90 = V(c)
83.3 = V(c)