Question

While an astronaut on planet X, you find a sample of an unknown liquid. Without your fancy equipment you decided to measure the mass of your spoon (25 grams, using local gravity) in and out of the liquid. In the liquid the scale reads 17.3 grams and it reads 18.9 grams in water. What is the density and the identity of the unknown liquid?

Answer 1

Solution:

Given,

mass of the spoon m=25g

mass of the spoon in liquid

mass of the spoon in water

Let the density of the liquid be and volume of spoon V.

The density of water is .

Let g be the acceleration due to gravity.

In liquid:

Upthrust is given by,  .

Upthrust = Actual weight - Apparent weight.

  

   ...........(1)

In water:

Upthrust is

Upthrust=Actual weight - Apparent weight.

  

  .

So, from eq.(1)

  

  

  

This is density of glycerin.