Question

using potential and kinetic energy quick check
two different rivers have drops that are the same height. in river a, this drop of the river is a waterfall. in river b, this drop has the generator for a hydroelectric dam. in what way does the energy of the water differ between the drops in the two rivers? (1 point)
the kinetic energy of the water would be less at the bottom of the drop in the waterfall river a than at the hydroelectric dam river b.
the potential energy of the water would be less at the top of the drop in the waterfall river a than at the hydroelectric dam in river b.
the kinetic energy of the water would be greater at the bottom of the drop in the waterfall river a than at the hydroelectric dam in river b.
the potential energy of the water would be greater at the top of the drop in the waterfall river a than at the hydroelectric dam in river b.

Explanation:

• Potential energy \(PE = mgh\) (where \(m\) is mass, \(g\) is acceleration due to gravity, \(h\) is height). Since the drops have the same height, the potential energy at the top is the same for both rivers.
• In a hydro - electric dam (river B), the generator converts some of the water's kinetic energy (as it falls) into electrical energy. So, the water at the bottom of the drop in river B has less kinetic energy compared to the water at the bottom of the waterfall (river A) where no such energy conversion (to non - kinetic energy) occurs.

Answer:

The kinetic energy of the water would be less at the bottom of the drop in the waterfall river A than at the hydroelectric dam river B.