Question

The energy of 4.72 kJ is the same as ______________ cal:

a.8.86
b.4.184
c.19 800
d.1.13
e.1130

Answer 1

To convert 4.72 kJ to calories, we use the conversion 1 cal = 4.184 J. Dividing 4720 J (equivalent to 4.72 kJ) by 4.184 J/cal yields 1130 calories, which corresponds to option (e).

Step-by-step explanation:

The question asks for the conversion of energy from kilojoules (kJ) to calories (cal). To convert the given energy of 4.72 kJ to calories, we use the conversion factor 1 kcal = 4184 J, or equivalently, 1 cal = 4.184 J. Hence, 4.72 kJ is equivalent to 4720 J (since 1 kJ = 1000 J). To find the calories, we divide 4720 J by the conversion factor:

Calories = 4720 J / 4.184 J/cal

Performing this calculation yields:

Calories = 1128.91 cal, which can be rounded to 1130 cal depending on the desired precision. Therefore, the correct answer is 1130 cal, which corresponds to option (e).

To convert the energy of 4.72 kJ to calories, we can use the conversion factor that 1 cal = 4.184 J. First, let's convert kJ to J by multiplying 4.72 kJ by 1000: 4.72 kJ x 1000 = 4720 J. Now, let's convert J to cal by dividing 4720 J by 4.184: 4720 J ÷ 4.184 J/cal = 1128.51 cal. Therefore, the energy of 4.72 kJ is approximately equal to 1128.51 cal.