Answer:
The bread will take 216.40 minutes to cool to 185°F
Explanation: Newton law of cooling
states that the rate of cooling of an object is inversely proportional to the difference of temperatures between the object and its surroundings i.e. dTdt=−kT, where t is the time taken and T is the difference of the temperatures between the object and its surroundings.
This gives us T as a function of t and is given by T(t)=ce−kt.
T(0)= Ce^-kt
C=35₩F- 185F= 165F
T(20) = 165×e^-20k=(350-70)
T(20)= e^-20k =280/165
-20k= ln(280/165)
-20k= ln(1.697)
-20k= 0.5289
K= 0.5289/20
K= 0.0264
If it cools at 185F in t minutes
165e^-0.0264×t=0.5
e^-0.0264t= 0.5/165
-0.0264t= on 3.03×10^-3
-0.0264t= -5.7129
t= 5.7129/0.0264
t=216.40minutes
Add different quantities of water to three potted plants
Answer:
B, B (decreases, a clockwise)
Explanation:
Finally, the switch on the electromagnet is reopened. The magnitude of the external magnetic flux through the wire loop <u>decreases</u>, and there is <u>a clockwise</u>, current induced in the loop (as seen from the left).
A droplet of pure mercury has a density of 13.6 g/cm3. What is the density of a sample of pure mercury that is 10 times as large as the droplet?
Answer: In this case the density will remain constant for both droplets. The reason being that volume will not change the density of the material. The only way of changing it is by changing its state. If you increase the volume then the mass will also increase. Leaving the density the same.
I hope it helps, Regards.
