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:
1,85 m / s²
Explanation:
De la pregunta anterior, se obtuvieron los siguientes datos:
Velocidad inicial (u) = 40 km / h
Hora inicial (t₁) = 0
Tiempo final (t₂) = 6 s
Velocidad final (v) = 0
Aceleración (a) =?
A continuación, convertiremos 40 km / ha m / s. Esto se puede obtener de la siguiente manera:
1 km / h = 0,2778 m / s
Por lo tanto,
40 km / h = 40 km / h × 0,2778 m / s / 1 km / h
40 km / h = 11,11 m / s
Por tanto, 40 km / h equivalen a 11,11 m / s.
Finalmente, determinaremos la aceleración del móvil durante el período en el que desaceleró. Esto se puede obtener de la siguiente manera:
Velocidad inicial (u) = 11,11 m / s
Hora inicial (t₁) = 0
Tiempo final (t₂) = 6 s
Velocidad final (v) = 0
Aceleración (a) =?
a = (v - u) / (t₂ - t₁)
a = (0 - 11,11) / (6 - 0)
a = - 11,11 / 6
a = –1,85 m / s²
Por tanto, la aceleración del móvil durante el período en el que se ralentizó es de –1,85 m / s²
Answer:
170 N
Explanation:
Given in the question that, work a bulldozer can do = 4500 J
<h3>
Step 1</h3>
We will use trigonometry identity to find the distance bulldozer will travel up the hill
sin(35) = opp/hypo
sin(35) = 15/hypo
hypo = 15/sin(35)
hypo = 26.15m
<h3>Step 2</h3>
Formula to use
work done = force × distance
Plug values in the above formula
4500 = force x 26.15
force = 4500/26.15
force = 172.08
force ≈ 170 N
<h3 /><h3 /><h3 />
16 kilometers is the answer i came up with. hope this helps.
Answer:
30.5 x 10³ min.
Explanation:
Atomic weight of aluminium = 27
For the reaction
Al⁺³ + 3e = Al
3 mole of electron is required by 1 mole of aluminium
3 x 96500 C of charge is required for 27 gram of aluminium
60.2 g aluminium will require
645.47 x 10³ C
So charge required = 645.47 x 10³ C
Now Charge = Current x time
Current ( given ) = 0.352A
Time = charge / current = 645.47 x 10³ / .352
=1833 x 10³ s
30.5 x 10³ minutes
