# If a pipe diameter decreases by half, does flow speed...?

#### Pigglyjuff

Increase by 2 or 4?

#### ebasappa

##### Momma said knock you out.
5+ Year Member
7+ Year Member
Assuming the flow rate (Q) is constant:

original formula Q= Area x Vel. ----> Q/Area = V

So area ---> pi(r^2)

So I would assume it would increase by 4?.....

#### sciencebooks

10+ Year Member
Assuming the flow rate (Q) is constant:

original formula Q= Area x Vel. ----> Q/Area = V

So area ---> pi(r^2)

So I would assume it would increase by 4?.....

Agreed.

#### dmf2682

##### Membership Revoked
Removed
Increase by 2 or 4?

increase by a FACTOR of 4. Not trying to be a douche but there's a difference there that could trap you if you're not careful

#### Pigglyjuff

increase by a FACTOR of 4. Not trying to be a douche but there's a difference there that could trap you if you're not careful

Well duh, who would think that it would just increase by an integer of 2 or 4...that doesn't make sense.

Last edited:

5+ Year Member
lol.

#### uclabruin8

10+ Year Member
Unless it is an ideal fluid. Flow rate would be constant for an ideal fluid and would follow the continuity equation: cross sectional area decreases, velocity increases.