Iam doing a average atomic mass question. i have the answer to it, but it says to round it to 3 decimal places. the answer is 39.89982753. i don't know whether to round it to just the 39.899 or to actually round it to it being 39.900. if anyone could that would be

Round to 39.900.

Explanation:

You want to round to three decimal places.

39.899 827 53

That means you must drop all the underlined digits.

The rule for rounding is: If the first figure dropped (8) is greater than 5, increase the last figure kept (9) by 1.

Then, rounding 39.899 827 53 to three decimal places gives 39.900.

answers: to make sure that all of the broken pieces of tablet were added to the water, to allow for fair comparison of all three trials, with different particle sizes to avoid experimental error

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.