Answer:
The volume flow rate of air is 
Explanation:
A random duct is shown in the below attached figure
The volume flow rate is defined as the volume of fluid that passes a section in unit amount of time
Now by definition of velocity we can see that 'v' m/s means that in 1 second the flow occupies a length of 'v' meters
From the attached figure we can see that
The volume of the prism that the flow occupies in 1 second equals

Hence the volume flow rate is 
Answer:

Explanation:
From the question we are told that:
Plane strain fracture toughness of 
Y value 
Stress level of
Generally the equation for length of a surface crack is mathematically given by



Therefore
in mm

Answer:
Engineers can design a train with a regenerative braking system
Explanation:
Assuming the point of the question is that the engineers want to focus on using energy efficiently when starting and stopping, they would likely want to consider a regenerative braking system. Such a system can store energy during braking so that it can be used during starting, reducing the amount of energy that must be supplied by an outside power source.
Answer:
option c is correct
47.2%
Explanation:
given data
consisting of refrigerant = 134 a
volume V = 0.01 m³/kg
pressure P = 1MPa = 1000 kPa
to find out
quality of the R 134a
solution
we will get here value of volume Vf and Vv from pressure table 60 kpa to 3 Mpa for 1 Mpa of R134 a
that is
Vf = 0.0008701 m³/kg
Vv = 0.0203 m³/kg
so we will apply here formula that is
quality = (V - Vf) / (Vv - Vf) ............1
put here value
quality = (0.01 - 0.0008701 ) / ( 0.0203 - 0.0008701 )
quality = 0.4698
so quality is 47 %
SO OPTION C IS CORRECT