How many times does a 160-lb person have to climb to the 86 th floor (1000 ft) of the Empire State building for the work to equal the energy in a Snickers bar and a Kit-Kat bar combined?

Answer 1

We're going to assume that we can ignore metabolic energy and consider only the energy required to raise that weight to that height. In reality, your body would constantly be generating heat (which uses energy) and moving sideways in addition to straight up (which also requires energy), but those are much harder to account for.

The website for Snickers says there are 250 calories in a Snickers bar. I assume that's for the standard size rather than "fun size" or "king size" or whatever. If the bar you had in mind is a different one, look on the label to get the actual calorie amount. and use the basic approach outlined below to get the answer.

Hershey's says that a Kit Kat bar has 210 calories.

That's a total of 460 calories. Those are "nutritional calories", which are in scientific terms kilocalories. 460 kilocalories is about 1,925 kilojoules (a joule is a newton-meter, so it's going to make things a lot easier later to have the energy in joules rather than calories).

160 pounds is about 712 newtons.

1000 feet is 304.8 meters. Let's just call it 305.

Work (which has the same units as energy) is force x distance, so a force of 712 newtons times a distance of 305 meters is about 217 kilojoules.

1,925 kilojoules divided by 217 kilojoules is about 8.87, so you'd have to climb it 8 times, then back up to the 75th floor or so.

This is just the nutritional energy. If you meant the mass-equivalent energy, it's a lot more ... around 392 billion times.

Answer 2

We're going to assume that we can ignore metabolic energy and consider only the energy required to raise that weight to that height. In reality, your body would constantly be generating heat (which uses energy) and moving sideways in addition to straight up (which also requires energy), but those are much harder to account for.

The website for Snickers says there are 250 calories in a Snickers bar. I assume that's for the standard size rather than "fun size" or "king size" or whatever. If the bar you had in mind is a different one, look on the label to get the actual calorie amount. and use the basic approach outlined below to get the answer.

SImilarly, Hershey's says that a Kit Kat bar has 210 calories.

That's a total of 460 calories. Those are "nutritional calories", which are in scientific terms kilocalories. 460 kilocalories is about 1,925 kilojoules (a joule is a newton-meter, so it's going to make things a lot easier later to have the energy in joules rather than calories).

160 pounds is about 712 newtons.

1000 feet is 304.8 meters. Let's just call it 305.

Work (which has the same units as energy) is force x distance, so a force of 712 newtons times a distance of 305 meters is about 217 kilojoules.

1,925 kilojoules divided by 217 kilojoules is about 8.87, so you'd have to climb it 8 times, then back up to the 75th floor or so.

This is just the nutritional energy. If you meant the mass-equivalent energy, it's a lot more ... around 392 billion times.