EK Study Group Friends unite -- I need some help...

[Docsaintrita71]

Hello to anyone/everyone who answers this thread. I hope studying is going well for you. As for me, I have some nagging questions - one in particular right now. I would really appreciate your help!! I'm reviewing EK Physics and one of the end of the section questions is STILL giving me a little trouble. Please help if you can. Here it is....THANKS! (EK Physics #34)

The owner of a warehouse asks an engineer to design a ramp which will reduce the force necessary to lift boxes to the top of a 1/2meter step. If there is only room enough for a 4meter ramp, what is the maximum factor by which the lifting force could be reduced. (Answer is D -- but, how do you get from 1/2 to 4 by a factor of 8???)
A. 1/2
B. 2
C. 4
D. 8

---

Members don't see this ad.

 

[sexyman]

Ha this one drove me crazy.

w=Fd

Since the work won't change and you are changing the distance from .5 to 4 you are decreasing the force by a factor of 8 because you needed to multiply .5 by 8 in order to get 4.

So basically because you increased the distance by a factor of 8 you decrease the force by a factor of 8.

I hope this makes sense, and I hope I am right lol.

 

[Kraazy]

Ha this one drove me crazy.

w=Fd

Since the work won't change and you are changing the distance from .5 to 4 you are decreasing the force by a factor of 8 because you needed to multiply .5 by 8 in order to get 4.

So basically because you increased the distance by a factor of 8 you decrease the force by a factor of 8.

I hope this makes sense, and I hope I am right lol.

That's right. My only gripe w/ this question is that it's not completely clear whether the 4m refers to the horizontal space available for the ramp or the hypothenuse of the ramp. The 2nd option was the only one that made sense given the info provided and the answer choices, but I was confused for a while there.

 

[Docsaintrita71]

I cannot TELL YOU how I racked my brain over this one. Thanks so much!!! That makes perfect sense -- but, I'm worried I won't be able to think like this on the real exam....well, I guess I'll keep plugging away at it until its second nature.

Ty, again!! If I have anymore questions, I hope I can I throw them up in this thread or a new one so that I won't waste precious time trying to figure it out on my own!! More heads are better than one. And please, if I can help anyone with any question, although I am no genius , I will definitely try to help!!

Ha this one drove me crazy.

w=Fd

Since the work won't change and you are changing the distance from .5 to 4 you are decreasing the force by a factor of 8 because you needed to multiply .5 by 8 in order to get 4.

So basically because you increased the distance by a factor of 8 you decrease the force by a factor of 8.

I hope this makes sense, and I hope I am right lol.