Newton's second law:
F = ma
F = net force, m = mass, a = acceleration
Isolate a:
a = F/m
We can see that for an object with larger mass, we would need to apply a larger force on it to accelerate it at the same rate.
Compared to the 10 ton ship, we would need 5 times more force to accelerate a 50 ton ship at the same rate.
