What Is the Average Volume Gained Each Day for a Newborn?

[frog210293]

Homework Statement

If the child's birth mass is 3.3 kg, birth rate =1.2×10−2 kg/d (baby gains that amount each day) A child is born after 39 weeks in its mother's womb.
Assuming the fetal density is 1020 kg/m^3, what is the average volume gained each day?

Homework Equations

The Attempt at a Solution

V=m/d
V=(1.2*10^-2)/1020
V=1.76*10^-5 which is incorrect??

 

[collinsmark]

Hell frog210293,

Welcome to Physics Forums!

V=(1.2*10^-2)/1020
V=1.76*10^-5 which is incorrect??

Redo your calculation. (1.2 x 10^-2 [kg d^-1])/(1020 [kg¹ m^-3]) ≠ 1.76 x 10^-5 [m³ d^-1].

 

[frog210293]

ohh woops i redid it with the brackets and came up with 1.18*10^-5 but this is still wrong?

 

[collinsmark]

ohh woops i redid it with the brackets and came up with 1.18*10^-5 but this is still wrong?

That's about the answer that I got.

Are you supposed to give your answer in m³ per day, or do you need to convert to some other units like liters per day (or cubic centimeters per day)?

Also, there are two ways to do the problem. You could trust the given mass rate of 1.2 × 10⁻² kg/d, or you could recalculate a more precise version given that the birth mass was 3.3 kg, and the time elapsed was 39 weeks. (You get almost the same rate of 1.2 × 10⁻² kg/d, but with more significant figures.)

Maybe the program is counting it wrong because you are not using the correct number of significant digits, maybe? I'm not sure.