Attack is a type of Knock. Attack is related to Attempt. Attempt is related to Make. Make is related to Force. 
Water is related to Paint. you are likely to find Paint in/at/on Can. 
Knock <--IsA-- Attack <--RelatedTo--> Attempt <--RelatedTo--> Make <--RelatedTo--> Force 
Water <--RelatedTo--> Paint --AtLocation--> Can 