A hydroelectric power plant uses spinning turbines to transform the kinetic energy of moving water into electric energy with efficiency. That is, of the kinetic energy becomes electric energy. A small hydroelectric plant at the base of a dam generates of electric power when the falling water has a speed of . What is the water flow rate—kilograms of water per second—through the turbines?
The water flow rate-kilograms of water per second through the turbines is .
From work energy theorem, work done by all the forces is equal to change in kinetic energy .
Assuming water starts from rest, hence, change in kinetic energy is,
As of kinetic energy is converted into electrical energy. Available kinetic energy is
Therefore, rate of water flow is
You need to raise a heavy block by pulling it with a massless rope. You can either (a) pull the block straight up height h, or (b) pull it up a long, frictionless plane inclined at a 15o angle until its height has increased by h. Assume you will move the block at constant speed either way. Will you do more work in case a or case b? Or is the work the same in both cases? Explain.
94% of StudySmarter users get better grades.Sign up for free