Answer:
Systematic errors.
Explanation:
The density of the aluminium was calculated by a human and this is not natural but can be due to errors in the calibration of the scale for measuring the weight or taking readings from the measuring cylinder.
Random errors are natural errors. Random errors in experimental measurements are caused by unknown and unpredictable changes in the experiment. Systematic errors are due to imprecision or problems with instruments.
20/40=0.5 g/cm^3 becuase, mass/volume=density.
The Answer is B : The water particles become locked in place.
The speed of a wave in a uniform medium doesn't depend on its wavelength.
