myleswatts1

27.08.2019 • 

Physics

Me with these questions as soon as possible i need to turn it
a 60 watt light bulb uses 60 joules of electrical energy every second. however, only 6 joules of electrical energy is converted into light energy each second.
a. what is the efficiency of the light bulb? give your answer as a percentage.
b. what do you think happens to the “lost” energy?
19. the work output is 300 joules for a machine that is 50% efficient. what is the work input?
20. a machine is 75% efficient. if 200 joules of work are put into the machine, how much work output does it produce?

Ответ:

Jsmooth8928

01.01.2022

Physics

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A. I believe this might be the answer but
6 J/60 J= .1
.1 x 100= 10%

b. I'm not sure of this question

19. I'm not sure if I did this correct way or if there is a better way (I'm rusty) 
300 J/.50 %= 600
600/100= 6 (answer)

20. (200 J)(.75%) = 150 (answer)
Check:
Efficiency: output/input x 100
150 J/200 J= .75
.75 x 100= 75%

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Ответ:

plshelpme53

14.05.2021

Physics

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7x(√x - 7√7) Multiply √7x to "√x" and "-7√7" respectively: 
√7x*√x - 7√7*√7x 
First is to simplify: √7x² - 7√7²x 
Extract the squares: x√7 - 7*7√x 

Then, we simplify: x√7 - 49√x 
After simplifying the equation, I got the answer x√7 - 49√x.

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