Question

According to McDonald's nutrition facts a provides kiloCalories of energy. (1 dietitian's calorie is 1000 physicist's calories.) A typical automobile lead-acid battery can supply 50 Ampere-hours at 12 Volts. We can compare these by converting the energy specifications to common units. The SI unit of energy is the Joule=1 Watt-second. One physicist's calorie is 4.2 Joules.
How many Joules are there in a ?
How many Joules are there in a car battery?
Which tastes better? :-)

Answer 1

I feel your pain, I can't get that McDonald's part correct either? This is what I tried:
The amount of energy for the McDonald"s was kiloCalories, which I assumed to be 1000 calories in the kilocalorie, I then multiplied the results again by 1000 as a one dietitians calorie equal 1000 physicist's calorie, then multiplied by 4.2 to get answer in Joules......wrong answer, can't figure it out lol.

Answer 2

If you think about this- and have ever been on a diet- the (dietician's) calories in a Big Mac are not 8xx,000 but less than 1,000. The text thus refers to the energy content of the sandwich in physicist's calories. The comment on the 1000:1 is an aside so people can reconcile the two. It's a bit confusing, I agree.

Answer 3

Thanks Bill_B, never been on a diet lol,so was unaware of the "reasonableness" of the data.

Answer 4

Macdonald ice cream of strawberry flour is delicious.

Answer 5

p=vi and then convert watt-hour to watt second as 1hour=3600sec

Answer 6

i wont suggest but you can simply google it....