# Calculating Power for Pumping Water to a Tower

• Nx2
In summary, to keep up a flow of water at a rate of 75 Liters per second, it would require a power of (1.0 kg•d/s)/hr.
Nx2
Hi guys, I was doing some homework when I got stuck on this question I came upon. It goes as follows...

Water is being pumped up to a water tower, which is 92.0m high. The flow rate up to the top the tower is 75L/s and each litre of water has a mass of 1.00kg. what power is required to keep up this flow rate to the tower?

Ok, so I know the formula for power is P = W/t, so I changed W into F•d and now my equation is P = (F•d)/t. then I changed F into mg and got the equation P = (mg•d)/t.
Ok, now I am not sure if what I am doing is right but I don’t know where to go from here… they gave me velocity but I don’t know what to do with it. Like I subbed all my values in like the mass, gravity and distance but I don’t know what to do with the “75L/s and each litre is 1.00kg.”…. any help would be appreciated, thanks.

- Tu

You have :
$$P = \frac {mgh}{t} = gh \cdot \frac {m}{t}$$

Does that help ?

ok... so... hmmm lol sorry i don't understand where that equation was derived from... h is height right?

Yes, h is the height. I just wrote what you had written and re-arranged the terms to bring out the factor (m/t). m/t is mass per unit time. Do you not know the value of this ?

sorry... yea... we never learned that b4.

Nx2 said:
sorry... yea... we never learned that b4.
I'm not sure what you mean by this. Do you now understand how to solve the problem, or don't you ?

ooo... ok i tried it and i got the answer!... thnx a lot i appreciate it. good help.

- Tu

yea i understand... thnx

## 1. What is the definition of power in physics?

Power is the rate at which work is done or energy is transferred. It is measured in units of watts (W) and is calculated by dividing work by time.

## 2. How is power related to force and velocity?

Power is directly related to both force and velocity. The formula for power is P = F * v, where P is power, F is force, and v is velocity. This means that the larger the force applied or the faster the object is moving, the greater the power.

## 3. What is the difference between average power and instantaneous power?

Average power is the power measured over a certain period of time, while instantaneous power is the power measured at a specific moment in time. Average power takes into account changes in power over time, while instantaneous power only reflects the power at a specific instant.

## 4. How is power related to energy?

Power and energy are closely related concepts. Power is the rate at which energy is transferred, and energy is the ability to do work. The more power that is applied, the faster energy is transferred and work is done.

## 5. Can power be negative in physics?

Yes, power can be negative in physics. This typically occurs when work is being done by a force in the opposite direction of motion. In this case, the power would be negative because work is being done at a negative rate.

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