# Losing weight using Physiscs

1. Sep 21, 2012

### EternityMech

so im going to use the potential energy law e=mgh to lose joules(fat) the problem is that whats the energy effiency of the body i cant find that anywhere. im climbing a 22.5m apartment building and my weight is 114kgs (im not fat just big boned)

2. Sep 21, 2012

### CWatters

Why not assume it's 100% efficient?

E = 114 * 9.8 * 22.5m = 25,000

1J = 0.24 calories

so 25,000J = 6000 Calories.

The bad news is that "calories" on a packet of food are actually kilocalories.

So one trip to the top burns just 6 food calories

http://www.weightlossresources.co.uk/calories.htm

3. Sep 21, 2012

### CWatters

Google suggest you should assume the body is about 20% efficient so multiply by 5. One trip up is about 30 food calories. Looks like a BigMac is about 490 food calories or 16 trips up.

Edit: Got to laugh. Google has already changed the banner advert I see at the top of the page from one adbertising solar panels to one advertising a weight loss system.

4. Sep 25, 2012

### EternityMech

16 trips just for a bigmac???!!! no wonder everybody is fat.

5. Sep 25, 2012

### dipole

Climbing stairs is incredibly tedious. You're better off doing something more enjoyable which you will commit to doing for a long period of time, and it's absolutely necessary to eat properly.