Advice.........?

You are working a on an experiment: you have a jar of pennies in front of you and you have to make a prediction about many pennies there actually is in the 2 litter jar, what would you predict and why? you are then coming up with ways to minimize errors: when you try to figure out mathematically how many pennies are in the jar. What would you do to minimize errors on such an experiment? Like would you 'zero' the balance and etc?Advice.........?
You would start by working out a 'packing density' as to how many pennies can fit into a given space.





You can probably guess this pretty well without doing any calculations. If you had a 2L jar full of pennies and you poured in water, how much water do you think it would take before it overflowed? You might guess that it would only take 300mL (85% packing density) or 400mL (80% packing density) to fill the space that is not occupied by pennies. It is surprising how good our brains are at this type of problem.





Knowing the dimensions of the jar and a penny, you can then calculate how many pennies are in the jar.





To take it further, you can calculate a probably packing density. Suppose that the pennies are in orderly stacks. If you have such cylinders touching each other, how much space is left over? It is basically the ratio between the area of a circle and the area of a square of the same side length / diameter.





(pi r^2) / (2r)^2 = pi / 4 = 79%.





The calculation is different if you imagine the cylinders pressed into the hollows between the next layer of cylinders, the way they would naturally fall if you were building a pile of logs, say.Advice.........?
here what is the mass of the jar and the pennie one at a time ,,think how big the jar and put one in look in your head yes and more you have the count , see do it up here you can just try

blushed