# Fluid Questions I'm Really Confused

1. Nov 22, 2004

Hey! I have been out of school sick for a week! I'm a little behind and having some trouble understanding some things. Here is a question that has me stumped.

An Amusement park is planning to build a water slide, and the park owners would like to use big giant corks (p= 0.28g/cm^3) as "floats" for young children. what volume of cork is need to keep 20 percent (by volume) of a 40kg child above water at the base of the slide(assume the density of the child is 1.01g/cm^3)?

I found that the 20% of 40kg = 8kg
and i found that the density of the child = 7.9207

when you take your car into the shop to have it worked on, a hydraulic lift is used. The diameter of the piston lifting your car and the base it sits on have a combined mass of 12000kg. the oil used in this lift has a density of 800kg/m^3.

A. How many apples would you need to place on the imput piston in order to hold up your car? A medium apple weighs approximately one newton.
B. When the car reaches a height of 0.15m, how many apples will it take to support the car at that height?

I don't even know where to start,i don't even know what they are talking about??