Calculate the output of a tidal barrage in mega watts if the basin is 30km2 and the tidal range is 6m.

E = PA R^2g/2
P = 1020Kg m-3
g = 9.81m-2
R = 6m
A = 30*10^6

The answer is 5.4*10^12j butwhat is this in mega watts

Thank you

jason

If you use an area of A = 30*10^6 m^2, in your formula, you will get the available energy in Joules. g = 9.81 m/s^2, NOT 9.81 m^-2. I agree with the 5.4*10^12 Joule answer. That is also 5.4*10^6 megajoules

There is no way of getting the power unless you know the period of time during which that energy is released. You have not provided the information necessary for that calculation. Perhaps the question meant to ask for Megajoules, not Megawatts.

To convert the energy in megajoules to megawatts, you need to know the time period over which that energy is released. Without this information, it is not possible to calculate the power output in megawatts.

However, if you have the time period, you can use the formula:

Power (in megawatts) = Energy (in megajoules) / Time (in seconds)

For example, if the time period is 1 hour (3600 seconds), you can convert the energy of 5.4*10^6 megajoules as follows:

Power = 5.4*10^6 megajoules / 3600 seconds

Simplifying this equation would give you the power output in megawatts.