Buoyancy

[joachim]

Can anyone answer this question:-
A mass of 5 tonnes and relative density of 9 lies on the sea bed, calculate the volume of wood of relative density 0.8 which when fastened to the mass will raise to the surface?
A 3.05m3
B 19.7m3
C 15.76m3
D 35.45m3

I can get close to 35.45m3 but not close enough, can anyone help?

 

[DrPhil]

Can anyone answer this question:-
A mass of 5 tonnes and relative density of 9 lies on the sea bed, calculate the volume of wood of relative density 0.8 which when fastened to the mass will raise to the surface?
A 3.05m3
B 19.7m3
C 15.76m3
D 35.45m3

I can get close to 35.45m3 but not close enough, can anyone help?

We have to see your work to check it!

In particular, I would like to see how you deal with units. I believe a metric "tonne" is 1000 kg ?
And relative density is a ratio to density of water at 1000 kg/m^3 ?
Unfortunately I don't come close to ANY of the multiple-choice answers - so I really need to see your work!