Work problem. Right answer, wrong units

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SUMMARY

The discussion centers on a physics problem involving the calculation of work required to pump water from an aquarium. The user initially confuses the units of work, expecting Newtons but mistakenly obtaining Newton-meters. The correct approach involves understanding that work is defined as force multiplied by distance, where force is measured in Newtons. The user acknowledges the need for clarity on the definition of work and its associated units.

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  • Understanding of basic physics concepts, specifically work and energy.
  • Familiarity with unit conversions in physics.
  • Knowledge of fluid density, particularly the density of water (1000 kg/m³).
  • Ability to apply formulas related to force and distance in practical scenarios.
NEXT STEPS
  • Review the definition of work in physics, focusing on the formula W = F × d.
  • Study unit conversions between different measurements of work, such as Joules and Newton-meters.
  • Explore examples of calculating work done on fluids in various contexts.
  • Investigate the implications of density on work calculations in fluid mechanics.
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Students studying physics, educators teaching work and energy concepts, and anyone involved in fluid mechanics or engineering applications requiring precise unit usage.

tony873004
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My answer should obviously be in Newtons, but I'm getting Netwon meters.

An aquarium, 2 m long, 1 m wide, and 1 m deep is full of water. Find the work needed to pump half the water out of the aquarium. (The density of water is 1000 kg/m3.)
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In a similar example in the book, they do the problem the same way, but they just throw the units in at the end, after they've computed the answer. I could do the same on this homework problem and get full credit, but I just got to know... :smile:


 
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What makes you think that unit is wrong? What's the definition of work?
 
oops... It's getting late. I don't know why I was expecting Newtons. Thanks!
 

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