180 is the degrees a straight line segment is. This means that
4x + 3x + 2x = 180.
Since these all have the same variable (x), then you can add the coefficients. (4,3,2)
9x = 180
180/9 = x
X = 20
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:
10.67
Step-by-step explanation:
The 10 stays as it is. The 2/3 is approximated by 0.67 (to the nearest hundredth). Thus, we have 10.67 to the nearest hundredth.
