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

AI Thread Summary
To determine the correct ratio of platform sides for a 25-kg boy to lift a 1,500-kg car, the relationship between the areas of the platforms must be considered. The force exerted by the boy is equal to the force exerted by the car scaled by the area ratio of the platforms. The area ratio can be calculated using the formula Fsmall = (Asmall/Alarge) * Flarge, leading to an area ratio of 1/60. Since the platforms are square, the ratio of the sides is the square root of the area ratio, resulting in a side ratio of approximately 1/7.75. This indicates that the ratio of the platform sides must be more than 6.0 for the boy to gently lift the car.
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!
 
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