Answer:
0.023 Pa*s
Explanation:
The surface area of the side of the inner cylinder is:
A = π*d*l
A = π*0.15*0.75 = 0.35 m^2
At 200 rpm the inner cylinder has a tangential speed of:
u = w * r
u = w * d/2
w = 200 rpm * 2π / 60 = 20.9 rad/s
u = 20.9 * 0.15 / 2 = 1.57 m/s
The torque is of 0.8 N*m, this means that the force is:
T = F * r
F = T / r
F = 2*T / d
For Newtoninan fluids with two plates moving respect of each other with a fluid between the viscous friction force would be:
F = μ*A*u / y
Where
μ: viscocity
y: separation between pates
A: surface area of the plates
Then:
2*T / d = μ*A*u/y
Rearranging:
μ = 2*T*y / (d*A*u)
μ = 2*0.8*0.0012 / (0.15*0.35*1.57) = 0.023 Pa*s
Answer:
B A and C
Explanation:
Given:
Specimen σ
σ
A +450 -150
B +300 -300
C +500 -200
Solution:
Compute the mean stress
σ
= (σ
+ σ
)/2
σ
= (450 + (-150)) / 2
= (450 - 150) / 2
= 300/2
σ
= 150 MPa
σ
= (300 + (-300))/2
= (300 - 300) / 2
= 0/2
σ
= 0 MPa
σ
= (500 + (-200))/2
= (500 - 200) / 2
= 300/2
σ
= 150 MPa
Compute stress amplitude:
σ
= (σ
- σ
)/2
σ
= (450 - (-150)) / 2
= (450 + 150) / 2
= 600/2
σ
= 300 MPa
σ
= (300- (-300)) / 2
= (300 + 300) / 2
= 600/2
σ
= 300 MPa
σ
= (500 - (-200))/2
= (500 + 200) / 2
= 700 / 2
σ
= 350 MPa
From the above results it is concluded that the longest fatigue lifetime is of specimen B because it has the minimum mean stress.
Next, the specimen A has the fatigue lifetime which is shorter than B but longer than specimen C.
In the last comes specimen C which has the shortest fatigue lifetime because it has the higher mean stress and highest stress amplitude.
Answer:
Q=q
also
q=it
Explanation:
How to find magnitude of net electric charge when current flows through a capacitor with initial charge?
A capacitor is a device used in storing electric charges. The unit of capacitance is measured in farad
To find the magnitude of net electric charge in a capacitor, we use the following relation
Q=q
Q=the magnitude of net electric charge in coulombs
t=the time for an electron tpo pass through the capacitor
R=the resistance of the capacitor , measured in ohms
C=the capacitance of the capacitor measures in Farad
q=initial quantity of charge
Having all the parameters above will make it possible to determine the net electric charge
Recall also that
q=it
quantity (coulombs)=current*time(s)