Judging that items and entities (Spiders and cave spiders excluded) move at about 15% of normal speed when falling or moving through a spider web, an item thrown on top of a web will fall through in about 24 seconds.
Hold down your use item key (right click by default).
A clock in Minecraft is a handheld item, it can't be placed like a decorative block. However what you can do is craft an Item Frame and put that on the wall, then put the clock on the item frame. That way you then have a wall-mounted clock.
Minecraft's Item ID's can be found on Minecraft Wiki. Link in related links.
A hopper can collect a dropped or thrown item into it. If there are multiple hoppers beneath the top one, the item that was stored into the hopper will drop down to the bottom hopper. (If there's a chest below or next to the hopper, connecting to the chest, the item will just be stored inside the chest.) This is a great away to quickly travel items down to next rooms into a chest without having to leave the room you are currently in.
No, you can't take one item from a Minecraft mod unless there is a separate mod which contains that one item.
You have to put it in an item frame by right clicking on it with the clock. It's the same with survival.
Streamlining is a way to help an item travel faster. Friction is nearly the exact opposite, as it will slow an item down.
Minecraft
The item ID for a diamond pick in Minecraft is 278. I have linked you below in the related links of a full list of all the ID's in Minecraft.
An item dropping through the air experiences Skin Resistance. That is the turbulence created by friction on the surface of the item passing down in the air. Also there are Updrafts which will slow the item down. NOTE: These problems are not present when the item is in a Vacuum (Space.)
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