Get Help And Discuss STEM Concepts From Math To Data Science & Financial Literacy
STEM Gender Equality | Join us on ZOOM | Spreading Mathematical Happiness

MathsGee is free of annoying ads. We want to keep it like this. You can help with your DONATION

0 like 0 dislike
44 views
A television using 1,000 W of power is turned on for 40 minutes.  How much energy is expended by the television during this time?
in Grade 12 Physical Sciences by Diamond (50,514 points) | 44 views

3 Answers

1 like 0 dislike
Best answer

There are 2 questions on this page, I'm answering the one:
A hair dryer with a resistance of 30 Ω is plugged into a 120-volt socket. If the hair dryer is used for 10 minutes, how much electrical energy is used?

R = 30 Ω                            W = V²t / R

V = 120 V                               = (120)² (600) / 30

t = 10 * 60 (600s)                    = 288 000 J

by Wooden (786 points)
selected by
0 like 1 dislike
E= P*t

=(1.000)*(40*60)

=(1.000)* (2400)

=2400 J
by Wooden (2,549 points)
0 like 1 dislike
E = Pt in Joules per second

=1000x40x60

=2,400,000 J/s
by Wooden (1,121 points)
0 0
The power is not 1000 W but 1 W and the units for energy is not J/s rather W.s which is equivalent to J.

Related questions

0 like 0 dislike
1 answer

Welcome to MathsGee Q&A Bank, Africa’s largest personalized STEM and Financial Literacy education network that helps people find answers to problems, connect with others and take action to improve their outcomes.


MathsGee Q&A is the STEM and Financial Literacy knowledge-sharing community where students and experts put their heads together to crack their toughest questions.


MathsGee is free of annoying ads. We want to keep it like this. You can help with your DONATION

Enter your email address:

11,560 questions
9,449 answers
100 comments
10,409 users