Newton's law of cooling says the rate of change of temperature is proportional to the difference between the object's temperature and the temperature of the environment.
Here, the object starts out at 200 °F, which is 133 °F greater than the environment temperature. 10 minutes later, the object is 195 °F, so is 128 °F greater than the environment. In other words, the temperature difference has decayed by a factor of 128/133 in 10 minutes.
The solution to the differential equation described by Newton's Law of Cooling can be written as the equation
T(t) = 67 + 133*(128/133)^(t/10)
where T is the object's temperature in °F and t is the time in minutes from when the object was placed in the 67 °F environment.
The equation
T(t) = 180
can be solved analytically, but it can be a bit easier to solve it graphically. A graphing calculator shows it takes
42.528 minutes for the temperature of the coffee to reach 180 °F.
Answer:
3 days
Step-by-step explanation:
First multiply 10 by 400 to find how many meters she runs each day.
10*400 = 4,000
1 kilometer = 1,000 meters
Now convert the meters to kilometers
To convert it to kilometers you divide 4,000 by 1,000, which equals 4 kilometers.
So she runs 4 kilometers each day.
Now divide 12 by 4 to find out how many days it will take to run 12 kilometers.
12/4 = 3 days
The answer I was got 5/7.
The answer would be $225
The question tells us that two 4hr shifts earns her $120. So, one 4hr shift would earn her $60 and from that we can find that an individual hour earns her $15. Then we would multiply the $ per hour ($60) by the amount of hours asked for (15hrs) and we would get $225.
Answer:B
Step-by-step explanation:
You get -3/4 for both slope intercept forms