Question

Water flows over a section of Niagara Falls at a rate of 1.2 × 106 kg/s and falls 29 m. The acceleration of gravity is 9.8 m/s 2 . How many 80 W bulbs can be lit with this power?

Answer 1

It can lit 4262500 Bulbs

Step-by-step explanation:

Power: This can be defined as the ratio of energy or work done to the time taken to do the work. The S.I unit of power is Watt

Power (P) = mgh/t.................................. Equation 1

P = fall rate × height × acceleration due to gravity............ Equation 2

Where m = mass, h = height, g = acceleration due to gravity

Given: Fall rate = 1.2×10⁶ kg/s, g = 9.8 m/s², h = 29 m

Substituting these values into Equation 2

Power = 1.2×10⁶× 9.8×29

Power = 341.04×10⁶ W

Power = 3.41 × 10⁸ W.

Therefore the total power generated by Niagara fall = 3.41 × 10⁸ W.

But, Number of bulbs it can lit = Total power/power of one bulb

Also Given: power of one bulb = 80 W

Therefore, Number of bulbs = 3.41×10⁸/80

Number of bulbs = 0.042625×10⁸

Number of bulbs = 4262500 Bulbs.

Therefore it can lit 4262500 Bulbs