Answer:
The efficiency of the kettle is 75%
Step-by-step explanation:
Given;
total input energy of the kettle, Qi = 1000 J
energy transferred as sound = 100 J
energy transferred as light = 50 J
energy transferred to surrounding = 100 J
Total lost energy = 100 J + 50 J + 100 J
Total lost energy = 250 J
Total output energy = 1000 J - 250 J = 750 J
Efficiency of the kettle is given by;
[tex]E_f =\frac{0utput \ energy}{1nput \ energy} *100\%\\\\E_f = \frac{750 \ J}{1000 \ J}*100\\\\ E_f = 75 \%[/tex]
Therefore, the efficiency of the kettle is 75%
