PT1.S3.Q21 - The energy an animal must expend to move uphill

_oshun1_

Can someone break this down for me like I'm 5 years old because I have no idea what is going on here. I feel like you have to assume whether or not the proportions are inverse or not and I dont really see how you could deduce that from the stim.

keets993

Me too. I feel like the correct ac is so left field it doesn't make sense. But at the same time it's really obvious to someone who knows surface area and stuff

EvetteCee

P1: Body weight = Energy animal needs to move uphill
P2: Surface area - Energy animal has to move uphill

Conclusion: Small animals can run uphill, while large animals slow down when moving uphill

So basically the premises are telling us that an animal's surface area determines how much energy they have while their body weight determines how much they actually need to move uphill.

Therefore, why do large animals slow down when they move uphill? Because they don't have enough energy to do so. And why is this? ---- because their body weight is bigger than their surface area.

This is what Answer Choice C says.

It might be easier to illustrate with another example

EX) A dog's surface area is 55, but he weighs 135. He only has 55 of engery to use, but he needs 135 to move uphill ...... so, he slows down because he does not have enough energy to keep running uphill.

Let me know if this kind of helps?

_oshun1_

@EvetteCee said:
P1: Body weight = Energy animal needs to move uphill
P2: Surface area - Energy animal has to move uphill

Conclusion: Small animals can run uphill, while large animals slow down when moving uphill

So basically the premises are telling us that an animal's surface area determines how much energy they have while their body weight determines how much they actually need to move uphill.

Therefore, why do large animals slow down when they move uphill? Because they don't have enough energy to do so. And why is this? ---- because their body weight is bigger than their surface area.

This is what Answer Choice C says.

It might be easier to illustrate with another example

EX) A dog's surface area is 55, but he weighs 135. He only has 55 of engery to use, but he needs 135 to move uphill ...... so, he slows down because he does not have enough energy to keep running uphill.

Let me know if this kind of helps?

Thank you it makes sense when you explain it like that. When I just read “proportional” I think of it as a ratio like I wrote out body weight: energy needed. Surface area:energy animal has to move uphill. I figured the first ratio was negative, the less you weigh, the less energy you need. And the second ratio is inverse, the smaller your surface area, the more energy you have to move up hill. I couldn’t get anywhere with that line of thinking so I think your explanation is more coherent.

keets993

@EvetteCee thanks, this question has been bugging me for a while. I totally didn't make the connection between the body weight being more than surface area. My line of reasoning was similar to surfy surf's so C kept throwing me off.