Its C .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... .......... ..........
Answer:
b. 2.3 kPa.
Explanation:
This situation can be modelled by Bernoulli's Principle, as there are no energy interaction throughout the multisection pipe and current lines exists between both ends. Likewise, this system have no significant change in gravitational potential energy since it is placed horizontally on the ground and is described by the following model:
Where:
, 
- Pressures at the beginning and at the end of the current line, measured in kilopascals.
- Water density, measured in kilograms per cubic meter.
, 
- Fluid velocity at the beginning and at the end of the current line, measured in meters per second.
Now, the pressure difference between these two points is:
If 
, 
and 
, then:
(1 kPa is equivalent to 1000 Pa)
Hence, the right answer is B.
Answer:
1) the mean surface temperature of earth.
2) precipitation and sunshine
3) air and wind movement.
Answer:
The final temperature in the vessel after the resistor has been operating for 30 min is 111.67°C
Explanation:
given information:
mass, m = 3 kg
initial temperature, T₁ = 40°C
current, I = 10 A
voltage, V = 50 V
time, t = 30 min = 1800 s
Heat for the system because of the resistance is
Q = V I t
where
V = voltage (V)
I = current (A)
t = time (s)
Q = heat transfer to the system (J)
so,
Q = V x I x t
= 50 x 10 x 1800
= 900000
= 9 x 10⁵ J
the heat transfer in the closed system is
Q = ΔU + W
where
U = internal energy
W = work done by the system
thus,
Q = ΔU + W
9 x 10⁵ = ΔU + 0, W = 0 because the tank is a well-insulated and rigid.
ΔU = 9 x 10⁵ J = 900 kJ
then, the energy change in the system is
ΔU = m c ΔT
ΔT = ΔU / m c, c = 4.186 J/g°C
= 900 / (3 x 4.186)
= 71.67°C
so,the final temperature (T₂)
ΔT = T₂ - T₁
T₂ = ΔT + T₁
= 71.67°C + 40°C
= 111.67°C
