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
Answer:
( -1, 15/2) or ( -1, 7 1/2)
Step-by-step explanation:
Formula: ( (x1 + x2)/2, (y1 + y2)/2 )
1. ( (-4 +6)/2, (8 + 7)/2 ) Plug in
2. ( -2/2, 15/2) Add/Subtract
3. ( -1, 15/2) or ( -1, 7 1/2) Divide
Answer:
Step-by-step explanation:
The question is not correct (particularly the expression for the area)
A=2lh+2wh
Now we are expected to solve for l, that is we are going to make l subject of the formula, we have
let us take the second term on the RHS to the LHS
we can now divide both sides by 2h we have
hence the expression for the length is
