Answer:
Choice D
Step-by-step explanation:
The distance increases at a steady rate from time = 0 to time = 1.
Then no progress is made between time = 1 and time = 2.
Then the distance increases at the same steady rate from time =2 to time = 3.
Finally, no progress is made between time = 3 and the end of the graph.
Eliminate Choices A, B and C immediately, because none of these scenarios involves a stop and wait.
That leaves only Choice D as a reasonable verbal description of what's happening here.
I think you may need a picture; nobody can help if we don’t know the size of the different sizes of the packages (:
Answer:
The refrigerator was at around 13 ∘C
Step-by-step explanation:
Newton's Law of Cooling:
The rate of change of a body temperature (amount of heat loss/time of loss) is directly proportional to the difference between its own temperature and the surroundings.
T ⇒ temperature
t ⇒ time
Tenv ⇒refrigerator temperature
⇒ rate of change of he temperature
-h ⇒ constant of proportionality (negative because the temperature is decreasing inside the refrigerator)
We have 3 points:
time (minutes) - Temperature (∘ C)
0 (when the pan was put in the refrigerator) - 46
15 (after 15 minutes) - 27
30 (15 minutes after the first 15 minutes) - 19
= -h (27 - Tenv)
= -h (19 - Tenv)
Now we have a system of two equations and two variables
The refrigerator was at around 13 ∘C
There are 75 girls because you add the ratio 3+5 = 8 then divide 120 by 8 to get 15 then there are 5 lots of girls so multiply 15 x 5 to get 75
hope this helps !
total distance travelled=72+69=141
time taken in hours for journey= (48/60)h + (69/60)= 1.95 h
average speed=141km/1.95h= 72.3km/h (3 sf)
