Please help with correct answer please! (:

If a cup of coffee has temperature 97Â°C in a room where the ambient air temperature is 25Â°C, then, according to Newton's Law o

FinnZ [79.3K]

Answer:

The average temperature is $T_{a} = 81.95^oC$

Step-by-step explanation:

From the question we are told that

The temperature of the coffee after time t is $T(t) = 25 + 72 e^{[-\frac{t}{45} ]}$

Now the average temperature during the first 22 minutes i.e fro $0 \to 22$ minutes is mathematically evaluated as

$T_{a} = \frac{1}{22-0} \int\limits^{22}_{0} {25 +72 e^{[-\frac{t}{45} ]}} \, dx$

$T_{a} = \frac{1}{22} [25 t + 72 [\frac{e^{[-\frac{t}{45} ]}}{-\frac{1}{45} } ] ] \left| 22} \atop {0}} \right.$

$T_{a} = \frac{1}{22} [25 t - 3240e^{[-\frac{t}{45} ]} ] \left | 45} \atop {{0}} \right.$

$T_{a} = \frac{1}{22} [25 (22) - 3240e^{[-\frac{22}{45} ]} - (- 3240e^{0} )]$

$T_{a} = \frac{1}{22} [550 - 1987.12 + 3240]$

$T_{a} = 81.95^oC$

8 0

2 years ago

At the movie theatre, child admission is S5.20 and adult admission is $8.30. On Tuesday, 156 tickets were sold for a total sales

Annette [7]

Answer:

So, 89 Adult tickets were sold.

Step-by-step explanation:

So, we first name our variables, say, a for number of adult tickets, and c for child tickets.

Then we write our system of equations, first the total $ sale:

5.2c + 8.3a = 1087.10

Then we write the 2nd equation, the total number of tickets:

c + a = 156

Now, we can solve the system:

We do have different methods, let's to by subsitution.

make some change to the 2nd equation, to make c the subject: c = 156 - a

Now we plug that into the 1st equation:

5.2(156 - a) + 8.3a = 1087.10

811.2 - 5.2a + 8.3a = 1087.10

811.2 + 3.1a = 1087.10

3.1a = 275.9

a = 89

8 0

3 years ago

What is the electric field strength at a distance of 15 cm from a point charge that has 12

ivann1987 [24]

The formula is E= kQ/ d^2

k is 9x10^9
i changed 15 cm to 0.15 m

=> 9x10^9 x 12 OVER (0.15)^2

the answer is 4.8x10^12 N/C

but this is the electric field.

to find electric field STRENGTH, it’s E= F/q and you did not give a value for the force

8 0

3 years ago

Combine the like terms to create an equivalent expression −5j+(−2j)+3

Oduvanchick [21]

Answer: -7j+3

Step-by-step explanation:Simplify

8 0

2 years ago

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Butoxors [25]

What is the importance of geometric figures in one’s life?

➪ Geometry plays an important role in our day to day life because it helps us in deciding material, design etc.. of an object. It also plays a vital role in construction process itself. Different types of houses and buildings are built using geometric shapes to give them a modern look.

6 0

2 years ago

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