Fluids:
Viscosity:
Description:
Coming soon!
Science:
Coming soon!
Special Requirements:
None.
Safety Procedures:
Ping Pong balls in Funnels:
Description:
Coming soon!
Science:
Coming soon!
Special Requirements:
None.
Safety Procedures:
Ping Pong balls in Funnels.pdf - 9kb
Buoyancy (weight of a finger):
Description:
Coming soon!
Science:
Coming soon!
Special Requirements:
None.
Bermuda Triangle:
Description:
Coming soon!
Science:
Coming soon!
Special Requirements:
Air pump. There are air vents in the UQ room 7-222 (and therefore the demo can easily be performed there). We currently do not have a portable air pump, however.
Safety Procedures:
Bernoulli:
Description:
Via a tube connected to a tap, water is forced through a fine glass tube apparatus*. The water flows along a horizontal tube at the bottom, and there are five connecting vertical tubes running from it, pointing upwards. The bottom, horizontal tube is wide initially, then narrows in the centre, and is wide at the other end once more. The water from the bottom tube is pushed up a certain distance into each of the vertical tubes; it can clearly be seen that the water level is lowest in the vertical tube above the narrowest section of the horizontal tube. It can also be noted that although the glass tube apparatus is symmetrical around its vertical centre, the heights of water in the tubes is not quite symmetrical. This indicates drag and turbulence effects at the point where the tube narrows since the pressures are not the same an equal distance after the narrow point.
Science:
This demonstrates Bernoulli's Principle, showing that at the point where the tube is narrowest, the fluid flows the fastest and according to Bernoulli's equation, the pressure is lowest. This means that the depth of fluid at that point will be lower.
Special Requirements:
A sink is required.
Sample Tutorial Questions:
- The vertical tube at the centre (above the narrowest point in the horizontal tube) has a fluid height of *cm. The outermost vertical tube (above the widest point in the horizontal tube) has a height of *cm. What is the difference in pressure between the bottoms of the two tubes?
- What is the absolute pressure at the bottom of each?
- Find an expression for the velocity of the fluid at the narrowest point in the tube in terms of just the velocity at the widest point in the tube. Estimate the velocity of water emerging from the tap, and use this to calculate the fluid velocity at the narrowest point in the tube. (Perhaps consider holding a hose that is turned on as far as it will go, and held horizontally. How far does the jet of water go before hitting the ground? What, therefore, was its initial horizontal velocity?)
- If the cross-sectional area at the point where each of the vertical and horizontal tubes meet is *cm 2 , what force is being exerted to maintain the column of water at the height it is at? Does it change your answer if the vertical tube widens further up?