M = W/g
mass (m)
weight (W) and strength of gravity (g)
Therefore the mass of the astronaut is 65 kilograms
Photosynthesis. Photosynthesis is the process the plant uses to absorbs light to make food
Accuracy is how close you're measurement comes to an accepted or given value. I n many cases you do not know what the accepted value is, so you have nothing to compare your measurement with. The more often a measurement is taken with close precision, or reproducibility, the more likely you are to being close to your unknown accepted value.
There is a great short tutorial video covering accuracy and precision at Sciocity dot com