1.5 m3 of water is mixed with 0.50 m3 of alcohol. the density of water is 1000 kg m–3 and the density of alcohol is 800 kg m–3.
what is the density of the mixture with volume 2.0 m3?

when two balls of the different masses are dropped from equal height, they reach the ground at the same time .this is because they experience the same acceleration.

the acceleration is independent of mass.

thus when they are dropped they will always maintain the same velocity and travel the same distance (neglect air resistance of course) at the same time.

because if the tool that you are using is not balanced it there would be false mass.