# How fast would an electric motor spin in space?

If you had an electric motor in space how fast would it spin since there is no friction? Would it build up to light speed?

There are lots of electric motors in space (all those satellites and their mechanisms...) and they behave exactly the same as on Earth.

russ_watters
Mentor
Being in a vacuum and 0g does very little to reduce the friction inside a motor.

Wouldn't it overheat easily without any atmosphere to transfer internal heat?

Drakkith
Staff Emeritus
Wouldn't it overheat easily without any atmosphere to transfer internal heat?

Yes it would.

Yes it would.

So the only way for the object to cool would be to expand. You would expect that any mechanical unit in space would explode eventually with no way to remove the heat.

DaveC426913
Gold Member
So the only way for the object to cool would be to expand. You would expect that any mechanical unit in space would explode eventually with no way to remove the heat.
1] There's no conduction and no convection, true, but there's still radiation, which is the method by which objects in vacuum transfer heat. But radiative cooling is comparatively slow.

2] While parts of the object will expand with heat, it will not go on indefinitely, and will not almost certainly not result in explosion. At some point, the heat will cause a part to fail - it might simply be a CB component burns out. The device stops working and stops producing heat.

1] There's no conduction and no convection, true, but there;s still radiation, which is hte meothd by which objects in vacuum transfer heat. But radiative cooling is compartively slow.

2] While parts of the object will expand with heat, it will not go on indefinitely, and will not almost certainly not result in explosion. At some point, the heat will cause a part to fail - it might simply be a CB component burns out. The device stops working and stops producing heat.

That is much more logical. Thanks.

So the only way for the object to cool would be to expand. You would expect that any mechanical unit in space would explode eventually with no way to remove the heat.

My understanding of heat is limited to my oven and summer time.

Pretty cool to consider what heat is.