Answer:
There is conversion of energy from one form to another and this justifies the law of conservation of energy, which states that energy can neither be created nor destroyed but can be converted from one form to another.
Explanation:
The fuel added to automobile is a chemical energy, which provides thermal energy of the combustion engine of the automobile, which is then converted to mechanical energy of the moving parts of the automobile. Thus, there is conversion of energy from one form to another. This justifies the law of conservation of energy, which states that energy can neither be created nor destroyed but can be converted from one form to another.
Answer:
Flow rate is 
Explanation:
Given information
Density of oil, 
kinematic viscosity, 
Diameter of pipe, D= 5 mm= 0.005 m
Length of pipe, L=40 m
Height of liquid, h= 3 m
Volume flow rate for horizontal pipe will be given by
where
is dynamic viscosity and
is pressure drop
At the bottom of the tank, pressure is given by

Since at the top pressure is zero, therefore change in pressure a difference between the pressure at the bottom and the top. It implies that change in pressure is still 
Dynamic viscosity, 
Now the volume flow rate will be

Proof of flow being laminar
The velocity of flow is given by

Reynolds number, 
Since the Reynolds number is less than 2300, the flow is laminar and the assumption is correct.
Answer:
The change in enthalpy of helium is 4073.86kJ/kg
Explanation:
∆H = Cp(T2 - T1)
Cp = 3.5R = 3.5×8.314 = 29.099kJ/kgmolK ÷ 2 (1kgmol of helium = 2kg of helium) = 14.5495kJ/kgK, T2 = 300°C = 300+273K = 573K, T1 = 20°C = 20+273K = 293K
∆H = 14.5495kJ/kgK(573K - 293K) = 14.5495kJ/kgK × 280K = 4073.86kJ/kg
Answer:
a) I_LED= 1/6 A b) Vf= 2.5V
Explanation:
Consider circuit in the attachment.
a) We will simplify current source in paraller with resistor to a voltage source in series with a resistor(see attachment 2)
Solving the circuit in attachment 2 using mesh analysis
-9+2I1+4(I1-I2)-4+2I1=0
8I1 - 4I2= 13 ............... eq 1
4+4(I2-I1)+ I2 + 2=0
4I1- 5I2 = 6 ............ eq 2
I1= 41/24 ; I2 = 1/6; I2= I_LED
b) Solving the circuit in attachment 2 again, this time I2=0
8I1 - 4I2= 13
8I1- 4(0)=13
I1= 13/8
Vf= 4(I1- I2) -4
I2=I_LED=0
Vf= 2.5 V