A hair dryer uses 2000J in 5 seconds when on full power. The power used is?

we are told that E = 2000J  and t = 5s  we need to find P

recall which formula used energy, time and power 

P = E/t 

sub in values 

P = 2000/5 

= 400 W (DONT FORGET UNITS) 

TF

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