motor efficiency

[searley]

This is what happens when you miss a week at collage and he is not giveing out answer sheets to work to,the git.

stuck with this one ?

An electric motor has an efficiency of 80% and an out put 0f 5kw ?

can anybody show me how to work it out ? cheers.

 

[Andy™]

output / efficiency x100

5/80 x 100

 

[Badger]

i got the answer of 6.25

am i correct or do i need to go back to college

 

[searley]

no you were right.

 

[Andy™]

i got the answer of 6.25 am i correct or do i need to go back to college

your right

but if you did get it wrong, i think it back to college to learn how to use a calculator!

 

[SPECIAL LOCATION]

This is what happens when you miss a week at collage and he is not giveing out answer sheets to work to,the git.stuck with this one ?

An electric motor has an efficiency of 80% and an out put 0f 5kw ?

can anybody show me how to work it out ? cheers.

The efficiency of anything can be easily considered as OUTPUT/INPUT

for an answer as a percentage you then multiply by 100.

Efficiency% = (OUTPUT/INPUT)x100

so start with sticking the bits you know

80=(5kw/INPUT)x100

transpose the formula give you the step AndyC quoted..

INPUT=(5kw/80)*100

=6.25kw

check your answer....

(5/6.25)*100 = 80!!!!