Answer:
6.38×10¯⁴ Calorie.
Step-by-step explanation:
The following data were obtained from the question:
Power (P) = 77 W
Time (t) = 8 h
Energy (E) =.?
Next, we shall convert 8 hours to seconds. This can be obtained as follow:
1 h = 3600 s
Therefore,
8 h = 8 h × 3600 s / 1h
8 h = 28800 s
Next, we shall determine the energy. This can be obtained as follow:
Power (P) = 77 W
Time (t) = 28800 s
Energy (E) =.?
Energy (E) = Power (P) / time (t)
E = P/t
E = 77 /28800
E = 2.67×10¯³ J
Finally, we shall convert 2.67×10¯³ J to calorie. This can be obtained as follow:
4.184 J = 1 calorie
Therefore,
2.67×10¯³ J = 2.67×10¯³ J × 1 Cal / 4.184 J
2.67×10¯³ J = 6.38×10¯⁴ Calorie.
Therefore, 6.38×10¯⁴ Calorie of food is used during the 8 hours period.