ought into contact 1- cubic-inch blocks of aluminum and lead, with the aluminum block at 100 ºC and the lead
lock at 0 ºC. What is the temperature of each block at thermal equili
ium, that is, when the
temperatures of the blocks are no longer changing?
2. Use the analysis of the power of flowing water (the Ho Ho Kus Brook) presented in the document 1, together with the equality Volume Flow = Flow Velocity x Cross Sectional Area of the flow to show that the power density of flowing water is given by a relation just like that for
the power density of flowing air in document 2 namely, for flowing water Power Density = ½
mass density of water x v3
For the same flow velocity, what is the ratio of the power density
of flowing air to the power density of flowing water?
3. Hydroelectric power is most commonly provided by building a dam and controlling
the flow of water through a tu
ine connected to a generator, as depicted in document 3. In
this case it is the change in potential energy of the water, ∆V=mg∆x, that is converted into
electrical energy by letting the potential energy of the water be converted into kinetic energy
as the water flows down to the tu
ine. The height of the water above the tu
ine, ∆x, is
ed to as the hydraulic head. If a dam had a hydraulic head of 100 m, what volume flow
would be needed to give an electrical power generation of 10 GW? You can assume 95%
conversion of the potential energy of water to electrical energy when using a
ine/electrical generator combination.