Question

The gravitational acceleration g at Earth’s surface actually depends slightly on latitude: this means that a ball that is dropped at the equator will accelerate slightly differently than one that is dropped in Ottawa in Canada. At Angel Falls in Venezuela (latitude 5°58'03'' N) the acceleration is about 9.78 m/s², while at Mount Ossa in Tasmania (latitude 41°52'12'' S) the acceleration is about 9.80 m/s². The difference may seem small, but which place would offer a higher power input P_in for a hydroelectric dam (if the water flow rate and water level drop are the same)?

Select one:

a. The power input would be equal.

b. Angel Falls, Venezuela.

c. Mount Ossa, Tasmania.

Answer 1

Option (c) ‘Mount Ossa, Tasmania’ is the correct answer.

Explanation –

The expression for the input power in the case of hydroelectric dam is given as –

Pin = Q*g*h ------------------------------(i)

where, Q = quantity of water flowing per second.

g = acceleration due to gravity

h = head of the water in the dam.

In our case, Q and ‘h’ are the same for both the places.

but value of ‘g’ is greater in the case of ‘Mount Ossa, Tasmania’.

Therefore, from equation (i), Pin will be greater in the case of Mount Ossa,Tasmania.