Question

rate of energy flow
the rate of energy flow is called power and it is measured in watts (w). a watt is equivalent to 1 joule/second, or 1 kg·m²/s³. you may be familiar with power from using electricity. light bulbs are described by the number of watts of electrical power they use. but power is used to describe the flow rates for all energy transformations. heat flow is the rate at which heat moves from one object to another. the rate that you cool off when you go outside on a cold day can be measured in watts.
power from water the amount of power available from a waterfall is dependent on the amount of water flowing and the height of the falls. compare the sizes of these two waterfalls.
the height and volume of this waterfall are much larger, resulting in greater gravitational potential energy and a higher rate of energy flow.
7 sep calculate 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?

Explanation:

Step1: Calculate gravitational - potential energy per second

The formula for gravitational potential energy per second is $E = m\times h\times g$, where $m = 2400000\ kg/s$, $h = 50\ m$, and $g=9.8\ m/s^{2}$.
$E=2400000\times50\times9.8$
$E = 1176000000\ J/s$
Since power $P$ (rate of energy flow) is energy per second and 1 watt = 1 J/s, the power $P$ of Niagara Falls is $P = 1176000000\ W$.

Step2: Calculate the number of light - bulbs

Let the power of each LED light - bulb be $P_{bulb}=15\ W$. The number of bulbs $n$ is given by $n=\frac{P}{P_{bulb}}$.
$n=\frac{1176000000}{15}$
$n = 78400000$

Answer:

The power of Niagara Falls is $1176000000\ W$ and the number of 15 - W LED light - bulbs it could power is 78400000.