A pure substance and a element
It is the atomic number. So it is D.
Answer:
1) The power of Niagara Falls is 1.176 × 10⁹ W
2) The number of 15 W LED light bulbs it could power is 78.4 × 10⁶ light bulbs
Explanation:
1) The Niagara falls water mass flow rate = 2,400,000 kg/s
The height of the fall = 50 meters
The gravitational potential energy = Mass (kg) × height (m) × gravity (9.8 m/s²)
The power = The energy converted per second = Mass flow rate (kg/s) × height (m) × gravity (9.8 m/s²)
Therefore;
The power of Niagara Falls= 2,400,000 kg/s × 50 m ×9.8 m/s²= 1.176 × 10⁹ W
The power of Niagara Falls = 1.176 × 10⁹ W
2) The number, n, of 15 W LED light bulbs it could power is given by the relation;
n × 15 W = 1.176 × 10⁹ W
∴ n = 1.176 × 10⁹ W/(15 W) = 78.4 × 10⁶ light bulbs
The number of 15 W LED light bulbs it could power = 78.4 × 10⁶ light bulbs.
