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?

The power of Niagara falls is 1,176 Mega Watts

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

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.

when the volume of gas is   changed from   717.73 ml   to 852 ml   the temperature will   change   from 315   c to 452   c

    calculation

this is calculated using the charles law formula

that is,   v1/t1 = v2/t2

          v1=?

        t1 = 315 c   into   kelvin = 315 +273 = 588 k

        v2 = 852   ml

        t2 = 425c + 273 =698 k

make v1   the subject of the formula ( by   multiplying both side by t1)

  v1=( v2 xt1) / t2

v1= (852 ml   x 588 k)/ 698 k= 717.73 ml

a is the correct answer