# their velocity or their velocities?

< Previous | Next >

#### Mechyao

##### Member
Their (A, B, C, etc.) velocity can be obtained by extrapolation method.
or
Their (A, B, C, etc.) velocities can be obtained by extrapolation method.

Likewise, "their pressure" or "their pressures"?

Thank you!

• #### Glenfarclas

##### Senior Member
Do they all have the same velocity, or do they have different velocities?

#### Mechyao

##### Member
Do they all have the same velocity, or do they have different velocities?
It depends. Sometimes I am mentioning that their velocities (or velocity) all increase (they may have different velocities or not).

#### Glenfarclas

##### Senior Member
If their velocities are being considered independently (although by chance they might happen to coincide), then you would use "velocities." It's the same answer as in this previous thread from a couple of weeks ago about "temperature vs. temperatures."

#### Mechyao

##### Member
If their velocities are being considered independently (although by chance they might happen to coincide), then you would use "velocities." It's the same answer as in this previous thread from a couple of weeks ago about "temperature vs. temperatures."
Thank you very much!

< Previous | Next >