Calculating Work Done by a 2HP Engine to Pump Water

[dreamgirl]

Homework Statement

A 2 Horsepower engine runs a water pump for 24 hours

a. What is the work done by the engine?
b. What would happen if a 1.0 horsepower was used to pump the same amount of water?

W= F * D

But i don't know what D is? so how must i solve this?
please help! :[

 

[Pengwuino]

Here's a hint, horsepower is not a force. It is actually a unit of power.

 

[nlightner]

I would first clarify that the units of horsepower (HP) and work (W) are not compatible. Work is typically measured in joules (J) or in the case of engines, in kilowatt-hours (kWh). Therefore, the question should be rephrased to ask for the work done in kilowatt-hours by the 2 HP engine.

Assuming that the engine is running at full capacity for the entire 24 hours, the work done can be calculated by multiplying the power of the engine (2 HP or approximately 1.49 kW) by the time it ran (24 hours or 86400 seconds). This gives a total work of approximately 129.6 kWh.

If a 1.0 horsepower engine was used instead, the work done would be halved to approximately 64.8 kWh. This is because the power of the engine is directly proportional to the amount of work it can do in a given amount of time. Therefore, a lower horsepower engine would require more time to pump the same amount of water, resulting in a lower amount of work done.

In order to calculate the work done in joules, the distance (D) over which the force (F) is applied would be needed. However, this information is not provided in the given question. Therefore, the work can only be calculated in kilowatt-hours using the given information.