What Is the Correct Ratio of Platform Sides to Lift a Car with a Boy's Weight?

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Homework Help Overview

The problem involves determining the ratio of the sides of two square platforms, one supporting a car and the other a boy, in order for the boy to lift the car. The context includes concepts from mechanics and the relationship between force and area.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the relationship between the ratio of platform sides and the ratio of areas, with some expressing uncertainty about how to differentiate between the two. There are attempts to apply the formula relating force and area to the problem.

Discussion Status

The discussion is ongoing, with participants exploring different interpretations of the problem. Some have provided guidance on calculating the area of a square, while others are questioning the assumptions made regarding the ratios involved.

Contextual Notes

Participants note the specific shapes of the platforms as squares, which influences the calculations. There is also a recognition of potential missing information or misunderstandings regarding the area ratio and its implications for the side ratio.

NY152
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Homework Statement


A 1,500-kg car stands on a square platform, and a 25-kg boy stands on another square platform. These platforms are the two caps of a large oil-filled container. What must the ratio of the platform sides (large/small) for the boy to gently lift the car?

-less than 1.5
-Between 3.0 and 4.4
-More than 6.0
-Between 1.5 and 2.9
-Between 4.5 and 6.0

Homework Equations


Fsmall= (Asmall/Alarge)*Flarge

The Attempt at a Solution



25*9.8 = (Asmall/Alarge)*(1500*9.8)
Asmall/Alarge =1/60
I know this is definitely not the right ratio, and I know I'm not including something probably in the area portion -I'm just not sure what that is
 
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How is the ratio of "the platform sides" related to the ratio of the areas?
 
TSny said:
How is the ratio of "the platform sides" related to the ratio of the areas?
I'm not sure, so the ratio of the platform sides would be different from the ratio of the areas, but I have no clue how you would decipher between the two...
 
The platforms are in the shape of a square. How do you calculate the area of a square if you know the length of the sides?
 
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TSny said:
The platforms are in the shape of a square. How do you calculate the area of a square if you know the length of the sides?
Oh I missed that it would be a square so you'd take the square root of the area ratio?
 
NY152 said:
Oh I missed that it would be a square so you'd take the square root of the area ratio?
Thanks that was right!