davisnaziyahovz5sk
12.11.2020 •
Mathematics
What is the solution of w – 4 = 18 + 3w?
Solved
Show answers
More tips
- H Health and Medicine Get Rid of Warts: Simple and Effective Ways...
- S Style and Beauty How to Choose the Perfect Hair Color?...
- C Computers and Internet Best iPad Games: Our Opinion...
- A Animals and plants Man s Best Friend: Which Dog Breed Is the Most Friendly?...
- H Health and Medicine 10 Simple Techniques on How to Boost Your Mood...
- G Goods and services How to Choose the Right High Chair for Your Baby?...
- S Style and Beauty Learn how to tie a keffiyeh on your head like a pro...
- S Style and Beauty How to braid friendship bracelets?...
Answers on questions: Mathematics
- M Mathematics All the members of a construction crew work at the same pace. six of them working together are able to pour foundation in 22 hours. c how many hours would this job take if the number...
- C Chemistry The half life for the radioactive decay of potassium-40 to argon-40 is 1.26 x 10^9 years. Suppose nuclear chemical analysis shows that there is 0.367 mmol of argon-40 for every 1.000...
- E English Which definition below describes shabbily? A. in a worn or messy manner B. having qualities of honor C.the study of magic tricks D. capable of being loved...
- F French Vous avez remarqué un changement bizarre dans le comportement d une personne que vous connaissez. décrivez-la avant et après le changement et trouver une explication fantastique...
- P Physics What is the average velocity v of the particle over the time interval î´t=50.0s?...
Ответ:
w=-11
Step-by-step explanation:
Move the w on to the right side:
-4=18+2w
Move the 18 to the left side:
-22=2w
Divide by 2
w=-11
Hope this helps!
And Brainlists plz!
Ответ:
the time of death td= 9:42 am
Step-by-step explanation:
If we suppose that a mass of constant heat capacity is cooled at a rate that is proportional to the temperature difference between the body and the environment then we can use an exponencial model for the body temperature as
T - T env = a*e^(-t/b)
then
if we use the reference t=0 as 10:30 am , then at t=0 , T= 76.3°F and
T - T env = a*e^(-t/b)
76.3°F-64°F = a*e^(-0/b)
a = 76.3°F-64°F = 12.3 °F
then for t= 0.5 hours (11:00 am from 10:30 am) ,T= 72.7°F and
T - T env = a*e^(-t/b)
72.7°F - 64°F = 12.3 °F*e^(-0.5 h /b)
b = -0.5 h/ln [( 72.7°F - 64°F) / 12.3 °F ] = 1.44 h
finally for Td=85.3°F the time of death td= is
Td - T env = a*e^(-td/b)
td= -b* ln[(Td - T env)/a]
td= - 1.44 h * ln[(85.3 °F - 64°F )/12.3 °F ] ]= - 0.79 h from 10:30 am
therefore
td= - 0.79 h*60 min/hour= -47.4 min from 10:30 am = 9:42 am
Note :
we applied the following physical model to end with the exponencial function
Q= m*c * (T-To) → dQ/dt= m*c*dT/dt
and -dQ/dT= U*A*(T- T env)
then
m*c*dT/dt = -U*A*(T- T env)
-dT/dt = U*A/(m*C) *(T - T env)
ln ( T- T env) = U*A/(m*C) (-t) + C
T- T env = e^(U*A/(m*C) t + C) = e^[U*A/(m*C)*(-t)] *e^C
T- T env = a*e^(-t/b)