Answer:
1. 0.574 kJ/kg
2. 315.7 MW
Explanation:
1. The mechanical energy per unit mass of the river is given by:


Where:
Ek is the kinetic energy
Ep is the potential energy
v is the speed of the river = 3 m/s
g is the gravity = 9.81 m/s²
h is the height = 58 m

Hence, the total mechanical energy of the river is 0.574 kJ/kg.
2. The power generation potential on the river is:

Therefore, the power generation potential of the entire river is 315.7 MW.
I hope it helps you!
Answer:
Option D, only on the portion of the Earth facing directly toward the Moon
Explanation:
Tides are caused by the gravitational pull of moon. The part of earth that faces the moon experiences the highest gravitational force and hence the high tides will occur in this regions only. The regions that do not faces the moon experiences low tides. It is the gravity of moon that attracts the ocean water towards itself.
Hence, Option D is correct
The last equation gives you the tension in the string on the right:

Answer:
Explanation:
On rubbing a glass rod with silk, the electrons from the glass rod get transferred to the silk. The silk now has an excess of electrons and so is negatively-charged. On the other hand, the glass rod is deficient in electrons and hence is positively-charged.
In the above case, the silk undergoes negative electrification.
Now, when the positively charged glass rod is touched on the disc of a negatively charged gold leaf electroscope, the electrons shifts towards rod, hence amount of charge on gold leaves decreases and the divergence between the gold leaves decreases as unlike charges attract each other.
Hence, the divergence decreases when a glass rod rubbed with silk is brought near the disc of negatively charged electroscope.
hope it helps pls mark me as brainliest
Answer:
A works to find magnitude. The leading negative sign gives us the positive magnitude after the correct velocity is found without it.