<span>The amount of dissolved oxygen in the Missouri River would decrease if large amounts of chemical waste were dumped into it. It would decrease because the chemical waste would feed on the microorganisms and reduce the amount of oxygen in the river.</span>
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:
10.2% of adults will belong to health clubs and will go to the club at least twice a week
Step-by-step explanation:
assuming that the event H=an adult belongs to a health club and the event T= he/she goes at least twice a week , then if both are independent of each other:
P(T∩H)= P(H)*P(T) ( probability of the union of independent events → multiplication rule )
replacing values
P(T∩H)= P(H)*P(T) = 0.20 * 0.51 =0.102
then 10.2% of adults will belong to health clubs and will go to the club at least twice a week