A staircase is considered a compound machine because it consists of multiple simple machines (such as inclined planes) working together to make it easier to move between different levels.
A roof is not a simple machine. It is a structure built to provide shelter and protection from the elements.
The stairs alone are not. A lever is a simple machine that is used to lift an object up easier because instead of pulling up against gravity you are pushing down with it but still lifting the same weight. A lever needs to have a pivot point which stairs don't have. This pivot point is called the fulcrum. Stairs are actually considered an incline plane, another type of simple machine.
A pin is classified as a type of fastener and not a simple machine. It is often used to secure two materials together.
A tack is a type of wedge, which is a simple machine that is used to push things apart or hold things together.
A projector screen is a type of lever simple machine when it is manually pulled down or rolled up. It can also be considered a pulley simple machine if it is motorized to retract or extend the screen.
iron
Screw, even though it has no moving parts. the spiral stairs of the Statue of Liberty are an oft-quoted example.
A spiral staircase is a type of screw. A spiral staircase is a type of screw.A spiral staircase is a screw. So it is an inclined plane.
Screw, even though it has no moving parts. the spiral stairs of the Statue of Liberty are an oft-quoted example.
A pulley isn't a kind of simple machine, it is a simple machine
A train is not a simple machine.
lever
IT's NOT A SIMPLE MACHINE!
its not a simple machine
It is a simple lever.
Rope is not a simple machine on its own, it's a simple machine on a wheel and axle, then it's a pulley.
a compound machine is a combination of simple machines