# Value of lava mass

This question has been posted before, and I amlooking for critque of my answer ..Thanks !!!!

The specific heat capacity of the lava is 1600 J kg^-1 degres celsuis ^-1. when all the erupted lava cools from the eruption temperature of 1050 degrees Celsius to 15 degrees celsius, the heat released is 2 x 10 ^15 J.
calculate a value for the total mass of lava that erupted. give your answer in scientific notation.

Is this the answer or can you help me where I go wrong !!

1600 J kg -1 °C -1 x 2 x 10 15 J x 1035 °C = 3.312 x 10 21 kgs

?????????????????

You haven't substituted correctly.
The equation is
q = mass x specific heat x delta T
q = heat released = 2E15 J.
mass = solve for this.
specific heat = 1600 J/kg*C
delta T = 1035
To solve for mass,
mass = q/(specific heat*1035) = ??kg.

Thank you !!!!

is this right

1.29375 x 10 15 kgs in sci notation ????

I get a slightly different number as well as a different exponent.
mass = q/sp.h.*delta T
mass = 2E15/1600*1035
mass = 1,207,729,468.60 kg.
In scientific notatin I would write that as
1.207 X 10^9 kg. Does your teacher pay attention to significant figures? Technically, there is only one allowed in the answer (the 2E15 has only one s.f.; i.e., the 2 unless the original problem was 2.00E15 or something like that) which would make the answer, with due regard to number of s.f. as 1E9 kg. Check my arithmetic. Check my thinking.

I have tried to get the same total as you...but still come back with the answer given above...

Divide by specific heat (1600). You should get 2E-15/1600 = 1.25E+12.
Now take that number and divide by the change in temperature (1050-15=1035).
1.25E+12/1035 = 1.207E9.

I was multipling the last figure instead of dividing..thank you very much !!!

I appreciate your time and trouble in helping me make sense of these questions.

Hi Freddo,the answer is 1*E9kg.One sig fig!

Be sure and watch the number of significant figures if your prof does. My earlier answer of 1E9 kg is the correct one; I wrote more s.f. in my last post because we were checking your calculator proficiency. Glad to be of help.

1. 👍 0
2. 👎 0
3. 👁 240

## Similar Questions

1. ### calorimetry

please, someone answer my question i posted already I answered your question within 15 minutes. It is posted. Hit the refresh button of your computer. sorry that my question took youthat long, but it was of great help. glad to

asked by claudia on January 18, 2007
2. ### bobpursley, drwls. ms. sue Writeacher

When a second post is made to a question, the most recent is now at the bottom. Do any of you prefer the way it was, or do you like this better? I prefer to have the answers shown in the order they were posted. The second answer

asked by Lance on June 16, 2005
3. ### Math

Good evening, I posted this question this morning. The answer that someone posted was not clear. Could someone please help me with this problem? x:9=2/3:36 The answer is 0.1666 But this is what I keep getting: x/9 = (2/3)/36 x *

asked by Anonymous on June 1, 2016
4. ### help help helppppp pleasee

ý posted some question of physics... please any one answer me.... qyestions are bellow ý posted before 3 hours...

5. ### To whoever "Anonymous" is

You posted this: Posted by Anonymous on Thursday, July 25, 2013 at 10:16am. Provide a brief overview of government policy toward Native American’s during the period of 1850 to 1900 and the impact this policy had on their lives.

asked by Writeacher on July 25, 2013
6. ### For Dr.Bob222

I posted a question under First Amendment, would you look at the question and give your opinion? I'm not finding it Carrie. I Posted the question under first amendment question I will pass since government is not my field.

asked by Carrie on January 25, 2007
7. ### General

Please understand that I am not upset with anyone or whatever I just want to know something. I have some work to be checked and the regular tutors here say that "we will be happy to critque your thinking" right? Ok so when someone

asked by Jon on April 1, 2008
8. ### math

Posted by mota THE MASS OF THE SUN IS ABOUT 10^27 METRIC TONS , OR 10^30 KILOGRAMS . HOW MANY KILOGRAMS ARE IN ONE METRIC TON ? ----------------------- math - drwls 1000. ----------------------- explain please i want to understand

asked by mota on March 2, 2008
9. ### MATH

WHY IS IT I NEVER GET AN ANSWER TO A QUESTION? IT SAYS I HAVE SUCCESSFULLY SUBMITTED THE QUESTION, BUT NEVER RECEIVE AN ANSWER. HOW DO I ACCESS AND ANSWER IF IN FACT, ONE IS POSTED?

asked by dorothy on January 22, 2014
10. ### BIO

I really need help with this question, Damon gave me an answer, but I do not know if it is for this question or for the one posted after. This is the only question I need help on, I promise not to post any other questions after

asked by Andrea on July 7, 2010

More Similar Questions