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

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The discussion revolves around a homework problem involving a steam iron that draws 8.0 A at 120 V, with the correct power rating calculated as 960 W. The user incorrectly calculated the energy produced in 20 minutes as 320 J, failing to account for the correct time conversion into seconds. The correct calculation requires multiplying the power (960 W) by the time in seconds, leading to a different energy output. Additionally, the cost to run the iron for 20 minutes at $0.010 per kWh was correctly calculated as $0.0032. The key takeaway is the importance of using the correct time unit when calculating energy in joules.
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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:
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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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Thread 'Variable mass system : water sprayed into a moving container'

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