Question

Water flows over Niagara Falls at the average rate of 2,400,000 kg/s, and the average height of the falls is about 50 m. Knowing that the gravitational potential energy of falling water per second = mass (kg) × height (m) × gravity (9.8 m/s2), what is the power of Niagara Falls? How many 15 W LED light bulbs could it power?

Answer 1

The power of Niagara falls is 1,176 Mega Watts

The number of 15 Watt bulbs it can power is 8,400,000 bulbs

Step-by-step explanation:

The rate at which the water falls given as the mass flow rate = 2,400,000 kg/s

The height from which the water falls = 50 m

The gravitational potential energy (potential energy PE.) of falling water = Mass (kg) × height (m) × gravity (9.8 m/s²)

The mass of water that falls per second = 2,400,000 kg

PE. = 2,400,000 kg × 50 m × 9.8 m/s² = 1,176,000,000 Joules

The power = The rate at which the energy is generated = The amount in kg of water that fall from the height per second × The height × Acceleration due to gravity

The power = 2,400,000 kg/s × 50 m × 9.8 m/s² = 1,176,000,000 Watts

The power of Niagara falls = 1,176,000,000 Watts = 1,176 Mega Watts

The number of 15 Watt bulbs it can power = 1,176,000,000/15 = 78,400,000 bulbs

The number of 15 Watt bulbs it can power = 8,400,000 bulbs.