The verb (beat), when used as an intransitive verb, comes with these three prepositions (against / on / at).
Can these prepositions be used completely alternatively?
For instance, 'Webster Dictionary' gives the following examples:
1- He beat at / against / on the door with his fists.
2- The waves were beating on / against the shore.
3- Nina managed to free herself and began beating at the flames with a pillow.
In 2: is it wrong to say (The waves were beating at the shore.)
In 3: is it wrong to say (Nina began beating against / on the flames with a pillow.)
Thanks in advance.