Perform each conversion.

(a) 345 Cal to kilowatt-hours

(b) 23 J to calories

(c) 5.7 × 103 J to kilojoules

(d) 326 kJ to joules

Solution 54P

Here, we are going to perform the given conversions.

Step 1:

Conversion of units can be done by a method called unit factor method based on the relationship between different units that expresses the same quantity.

Step 2:

Converting calorie(cal) to kilowatt-hours(kWh)1 cal = 1.163 x 10-6 kWh

1 = 1.163 x 10-6 kWh / 1 cal

1.163 x 10-6 kWh / 1 cal is called the conversion factor. Any measurement in calories can be converted to kilowatt-hours by simply multiplying the given quantity with the conversion factor.

Thus, 345 cal = 345 cal x = 0.000401235 kWh

Step 3:

b) Converting Joule(J) to calories(cal)

1 J = 0.2389 cal

1 = 0.2389 cal / 1 J

0.2389 cal / 1 J is called the conversion factor. Any measurement in joule can be converted to calories by simply multiplying the given quantity with the conversion factor.

Thus, 23 J = 23 J x = 5.4947 cal.