# Fluid statics question

#### NY152

1. 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

2. Homework Equations
Fsmall= (Asmall/Alarge)*Flarge

3. 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

Related Introductory Physics Homework Help News on Phys.org

#### TSny

Homework Helper
Gold Member
How is the ratio of "the platform sides" related to the ratio of the areas?

#### NY152

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...

#### TSny

Homework Helper
Gold Member
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?

• NY152

#### NY152

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

Oh I missed that it would be a square so you'd take the square root of the area ratio?
Thanks that was right!

### Want to reply to this thread?

"Fluid statics question"

### Physics Forums Values

We Value Quality
• Topics based on mainstream science
• Proper English grammar and spelling
We Value Civility
• Positive and compassionate attitudes
• Patience while debating
We Value Productivity
• Disciplined to remain on-topic
• Recognition of own weaknesses
• Solo and co-op problem solving