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:
Step-by-step explanation:
x^2=20
just square both sides and u get
x = 4.472135955
This is the concept of algebra. The value of x three times less than the value of 45-10x will be as follows;
The value of x three times is:
3x
subtracting 45-10x we get:
3x-(45-10x)
3x+10x-45
13x-45
the answer is:
13x-45
