Answer:
Step-by-step explanation:
The question in English is
In one appliance store, a refrigerator cost $8,900 and they lowered it to $7,120. What percentage did they lower?
we know that
$8,900 ------> represent the 100%
so
by proportion
therefore
the percentage is equal to
Answer:
a) : at time t = 2 minutes the temperature will be 8.265 degress
b) : the temperature will be 6 degrees at time t = 3.55 minutes.
Step-by-step explanation:
When dealing with temperature changes, it's best to work with Newton's Law of Cooling.
here:
: the temperature in the room.
: ambient (or outdoor) temperature (that always remains constant, in our case:
)
: are constants
Our conditions are provided:
1)
2)
using the first condition
using the second condition:
we can use our calculated value of C to find k
Finally we can put these constants back in the main equation:
or
a) Reading after one more minute?
so it's asking:
T(2) = ?
Hence, after one more minute the temperature of the room will be 8.267 degrees
b) When will it be 6 degrees?
T(t) = 6?
Hence at t = 3.55 minutes the temperature of the room will be 6 degrees.