I have to fight the Golem with a trash can....
Given that the Golem's probably made of a durable substance like ceramics or stone, throwing the can as a weapon would be a stupid idea - the can is going to go to pieces long before Golem. Its contents are mostly things like scrap cardboard and used tissues, so there's nothing inside that can be a viable throwing weapon.
Using the can or its contents as a shield will probably not work, either. The Golem's fists would send me flying regardless if I hold the can in front of me because of the sheer force of the punch. A pile of used tissues wouldn't absorb the hit, either. The metal can probably could protect from the fireballs, but those can be dodged with a bit of effort. It appears that I can't use my item as a shield.
What
can I use it for, then?
Well, depending on the heat of the fireballs the Golem shoots, it
may be hot enough to cause the can to melt (it would have to be
very hot, though. The lasers
might stand a better chance of reaching the melting point). It'd be very risky and/or painful, but if I can get the half-melted metal and somehow (perhaps utilizing the room design or the traps in some way) sling it onto the Golem's face, then it may cool down on its face and prevent the Golem from shooting fireballs and lasers. From there, with my half-melted trash can stuck on the Golem's face, I can use any traps scattered around the room to take out the rest of its body while only dealing with the fists and the body, which are easier to dodge and vulnerable to attack (you can't hurt the Golem by attacking the fireballs it shoots...). All I have to do from there is to whittle its health down with traps until it's defeated.
I don't care that the trash can didn't last long. It still might've done something to help, assuming the fireballs/lasers really are hot enough to melt the can. Also,
logic, this is Terraria. I can open the crafting menu and turn the trash can into a machine gun.