An object is made of glass and has the shape of a cube 0.13 m on a side, according to an observer at rest relative to it. However, an observer moving at high speed parallel to one of the object's edges and knowing that the object's mass is 2.0 kg determines its density to be 7300 kg/m3, which is much greater than the density of glass. What is the moving observer's speed (in units of c) relative to the cube

The  velocity is  

Explanation:

From the  question we are told that

   The side of the cube is  

   The  mass of the object is  

   The  density of the object is  

Generally the volume of the object according to the moving observer is mathematically represented  as

Therefore the length of the side as observed by the observer on high speed is mathematically represented as

Now the original length of side is mathematically represented as

Where c is the speed of light with value

So

=>  

=>