Newton's Law of Cooling
Tf=Ts+(Ti-Ts)e^(-kt) where Tf is temp at time t, Ts is temp of surroundings, Ti is temp of object/fluid. So we need to find k first.
200=68+(210-68)e^(-10k)
132=142e^(-10k)
132/142=e^(-10k)
ln(132/142)=-10k
k=-ln(132/142)/10
k≈0.0073 so
T(t)=68+142e^(-0.0073t) so how long until it reaches 180°?
180=68+142e^(-0.0073t)
112=142e^(-0.0073t)
112/142=e^(-0.0073t)
ln(112/142)=-0.0073t
t= -ln(112/142)/(0.0073)
t≈32.51 minutes
I feel like its either b or c
Answer:
<h2>
3,654 different ways.</h2>
Step-by-step explanation:
If there are 30 students in a class with natasha in the class and natasha is to select four leaders in the class of which she is already part of the selection, this means there are 3 more leaders needed to be selected among the remaining 29 students (natasha being an exception).
Using the combination formula since we are selecting and combination has to do with selection, If r object are to selected from n pool of objects, this can be done in nCr number of ways.
nCr = n!/(n-r)!r!
Sinca natasha is to select 3 more leaders from the remaining 29students, this can be done in 29C3 number of ways.
29C3 = 29!/(29-3)!3!
29C3 = 29!/(26!)!3!
29C3 = 29*28*27*26!/26!3*2
29C3 = 29*28*27/6
29C3 = 3,654 different ways.
This means that there are 3,654 different ways to select the 4 leaders so that natasha is one of the leaders
Hi there!
(3/2)2+4<span>÷2*3 = 9
Hope this helps! :)</span>
Answer:
See below in bold.
Step-by-step explanation:
Use the point-slope form of a straight line
y - y1 = m(x - x1)
Here m = -5/9 , x1 = 9 and y1 = -3:, so
y - -3 = -5/9(x - 9)
y + 3 = -5/9x + 5
y = -5/9x + 2 is the equation parallel to the given line.
The line perpendicular to the given line will have a slope of - 1 / -5/9
= 9/5 so its equation is
y + 3 = 9/5(x - 9)
y = 9/5x - 81/5 - 3
y = 9/5x - 96/5 .
