Webassign due in like half hour i have the problem down but its not working

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SUMMARY

The discussion centers on a physics homework problem involving a steam iron that draws 8.0 A at 120 V. The correct power rating is established as 960 W. However, the calculation for energy produced in 20.0 minutes is incorrectly stated as 320 J; the correct approach requires converting time to seconds, leading to a total energy output of 1,152,000 J. The cost to run the iron for 20.0 minutes is accurately calculated at $0.0032.

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webassign due in like half hour! i have the problem down...but its not working!

Homework Statement



A steam iron draws 8.0 A when connected to a potential difference of 120 V.
(a) What is the power rating of this iron? 960 W <<<<correct

(b) How many joules of energy are produced in 20.0 min?
320 J <<<incorrect why?

(c) How much does it cost to run the iron for 20.0 min at $0.010/kW·h?
.0032 $ <<<<correct


Homework Equations



for part b: 960*(20/60) = 320

whys it wrong?!
 
Last edited:
Physics news on Phys.org
One Watt = one Joule per second. You need to multiply the power (960 W) by the time in seconds (not hours).
 

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