Calculating Buoyancy in Oil/Water: Solving for Height of Cylinder

[ncote]

1. A solid cylinder (radius = 0.150 m, height = 0.120 m) has a mass of 6.90 kg. This cylinder is floating in water. Then oil ( = 725 kg/m3) is poured on top of the water until the situation shown in the drawing results. How much of the height of the cylinder is in the oil?



2. (p)water(g)(V)water + (p) oil(g)(V) oil= mg
(V)water+ (V)oil= (V)cylinder
(h)oil= (V)oil/area of cylinder



3. using what i was given, i was able to calculate the area and volume of the cyclinder, which was easy enough. i know that once i use the first equation to get the volume of the oil I am supposed to subtract it from the volume of the cylinder. unfortunately I am not sure how to figure out the volume of the oil using the equation we were given (the first one i listed)

 

[Shooting Star]

I can't see any drawing.

 

[ncote]

I can't see any drawing.

http://smg.photobucket.com/albums/v456/andpull/?action=view&current=cylinder.gif

 

[Shooting Star]

Total buoyant force upward = weight of water displaced + weight of oil displaced. Is this enough for you to proceed?

Take h as the height of the cylinder in oil. Then H-h is in water, where H is ht of cylinder. Try it out.