A solid brass statue weighs 190 N in air?

Question

a. what is its volume?
b. the statue is suspended from a rope and totally immersed in water. what is the tension in the rope (the apparent weight of the statue in water)?

Answer 1

a. The mass of the statue is (let's see, W=mg) W/g = 190 N/9.8 m/s^2 = 190 (kg*m/s^2)/9.8 (m/s^2) = 19.4 kg. The density of brass is 8.5*10^3 kg/m^3. So to calculate the statue's volume
19.4 kg * (1 m^3/8.5*10^3 kg) = .0023 m^3.

b. The mass of that volume of water
.0023 m^3 * (1 kg/1*10^3 m^3) = 2.3 kg.

The weight of the statue: 190 Newtons
The weight of the 2.3 kg water: 2.3 kg*9.8 m/s^2 = 22.3 Newtons. This is the amount of bouyancy provided by the water.

So the tension in the cable while the statue is under water is 190 - 22.3 Newtons = 168 Newtons. And it doesn't matter how deep you lower the statue, the water's density stays the same so the bouyancy stays the same.

Answer 2

A) you need the density
B) How deep? If the statue is lowered far enough, it will become bouyant and there will be no tension in the rope.

Answer 3

a. In order to solve this, you need to know density of brass,x.
cc / xNewtons * 190 Newtons = volume in cc

b. have to think about this one.