# Physics equations/12-Fluid dynamics/Q:pipeDiameterChange

## 12-pipeDiameterChange Version A

A 6.3 cm diameter pipe can fill a 2.2 m^3 volume in 4.0 minutes. Before exiting the pipe, the diameter is reduced to 4.6 cm (with no loss of flow rate).

1 What is the speed in the first (wider) pipe?

 a) 1.65E0 m/s b) 2.00E0 m/s c) 2.43E0 m/s d) 2.94E0 m/s e) 3.56E0 m/s

2 Referring to the previous question, what is the pressure difference (in Pascals) between the two regions of the pipe?

 a) 8.99E3 b) 1.09E4 c) 1.32E4 d) 1.60E4 e) 1.94E4

3 Referring to the previous question, if two fluid elements at the center of the pipe are separated by 33.0 mm when they are both in the wide pipe, and we neglect turbulence, what is the separation when both are in the narrow pipe?

 a) 6.19E1 mm b) 7.50E1 mm c) 9.09E1 mm d) 1.10E2 mm e) 1.33E2 mm

4 A large cylinder is filled with water so that the bottom is 7.7 m below the waterline. At the bottom is a small hole with a diameter of 6.4E-4 m. How fast is the water flowing at the hole? (Neglect viscous effects, turbulence, and also assume that the hole is so small that no significant motion occurs at the top of the cylinder.)

 a) 8.37E0 m/s b) 1.01E1 m/s c) 1.23E1 m/s d) 1.49E1 m/s e) 1.80E1 m/s

## pe12pipeDiameterChange Version B

A 8.8 cm diameter pipe can fill a 2.4 m^3 volume in 5.0 minutes. Before exiting the pipe, the diameter is reduced to 3.9 cm (with no loss of flow rate).

1 What is the speed in the first (wider) pipe?

 a) 8.96E-1 m/s b) 1.09E0 m/s c) 1.32E0 m/s d) 1.59E0 m/s e) 1.93E0 m/s

2 Referring to the previous question, what is the pressure difference (in Pascals) between the two regions of the pipe?

 a) 2.16E4 b) 2.61E4 c) 3.16E4 d) 3.83E4 e) 4.64E4

3 Referring to the previous question, if two fluid elements at the center of the pipe are separated by 21.0 mm when they are both in the wide pipe, and we neglect turbulence, what is the separation when both are in the narrow pipe?

 a) 1.07E2 mm b) 1.30E2 mm c) 1.57E2 mm d) 1.90E2 mm e) 2.30E2 mm

4 A large cylinder is filled with water so that the bottom is 6.0 m below the waterline. At the bottom is a small hole with a diameter of 5.9E-4 m. How fast is the water flowing at the hole? (Neglect viscous effects, turbulence, and also assume that the hole is so small that no significant motion occurs at the top of the cylinder.)

 a) 6.10E0 m/s b) 7.39E0 m/s c) 8.95E0 m/s d) 1.08E1 m/s e) 1.31E1 m/s

1. Thanks to user:Clockworks, this is one of the first numerical wikiquizzes generated by something other than MS Excel in the summer of 2014.