Answer:
= 85.7 ° C
Explanation:
For this exercise we will use the calorimetry heat ratios, let's start with the heat lost by the evaporation of coffee, since it changes from liquid to vapor state
Q₁ = m L
Where m is the evaporated mass (m = 2.00 103-3kg) and L is 2.26 106 J / kg, where we use the latent heat of the water
Q₁ = 2.00 10⁻³ 2.26 10⁶
Q1 = 4.52 10³ J
Now the heat of coffee in the cup, which does not change state is
Q coffee = M 
( -
)
Since the only form of energy transfer is terminated, the heat transferred is equal to the evaporated heat
Qc = - Q₁
M ce ( -) = - Q₁
The coffee dough left in the cup after evaporation is
M = 250 -2 = 248 g = 0.248 kg
-Ti = -Q1 / M
= Ti - Q1 / M
Since coffee is essentially water, let's use the specific heat of water,
= 4186 J / kg ºC
Let's calculate
= 90.0 - 4.52 103 / (0.248 4.186 103)
= 90- 4.35
= 85.65 ° C
= 85.7 ° C
Answer: 1 dioptre of power of a lens is defined as the unit of measuring the power of optical lens Or curved mirror which is equal to the reciprocal of the focal length. The focal length is measured in the meter. 1 dioptre is equal to 1/m where m is the focal length. Basically dioptre is the SI unit of optical power of the lens.
Answer:
Explanation:
circumference of the tyre = 2πr = 2 x 3.14 x 0.26 = 1.6328m
76000km = 76000000m
no of revolutions required
= 76000000/1.6328 = 46546 revolutions.
Answer:
Explanation: find the attached solution below
<h3><u>Answer;</u></h3>
Argon
<h3><u>Explanation;</u></h3>
- Phosphorus is an element found in group 15 of the periodic table, it is one of the element that belongs to nitrogen family.
- The element phosphorus exhibits allotrophy, namely; white phosphorus, red phosphorus and black phosphorus.
- <u>Phosphorus, particularly the white phosphorus combines with oxygen so easily that it catches fire automatically. Thus, as a safety precaution, white phosphorus is stored under water in laboratories.
</u>
- <u>It may be also stored in argon, since argon is an inert element which belongs to the noble gases group.</u>
