This is the question from the text book:
enter image description here

This is what I did, since it worked with all the previous questions (similar to this).

$$ \frac{\frac{4}{3}\pi(7*10^8)^3*1.4}{1.008} * 6.022*10^{23} $$

This equals $1.2 *10^{51}$, but the answer is $1.2*10^{57}$

What have I done wrong? Thank you in advance.


The problem is that you did not include units with your numbers. If you had, you would have easily seen that you are multiplying $m^3$ and $cm^{−3}$ and coming up with 1 instead of 1000000.

  • $\begingroup$ Thank you! I forgot to convert the radius, stupid mistake. Thank you again! $\endgroup$ Jun 1 '14 at 0:13

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.