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:
The reflection and rectilinear propagation of light helps in the formation of shadows and also tells light doesn't penetrate opaque materials.
Answer:
Explanation:
Magnetic field near current carrying wire
= 
i is current , r is distance from wire
B = 10⁻⁷ x 
force on second wire per unit length
B I L , I is current in second wire , L is length of wire
= 10⁻⁷ x x 33 x 1
= 3234 x 
This should balance weight of second wire per unit length
3234 x = .075
r = 
x 10⁻⁷
= .0043 m
= .43 cm .
Answer:
A. attracted to the negative terminal of the voltage source.
Explanation:
When an electron is displaced in a semiconductor, the hole that's left behind is
A. attracted to the negative terminal of the voltage source.
The electron leaving leaves a net + charge, which is attracted to the negative terminal.
Answer:
Selenium is a semiconductor
Explanation:
Selenium is a semiconductor.
Elements in the column IV and VI of the periodic table are referred to as Semiconductor.
Selenium lies in the column VI along with Tellurium
Some other elements of the column IV are silicon, germanium, and tin
