Why 1+12+ Y3 < 1100
Says the state of university Need to purchase 1100 computers in total, we have the following answer on the way top
Answer:
81.76 N/mm² ( MPa), 1.71233
Explanation:
Modulus of elasticity = stress / strain
stress = modulus of elastic × strain
strain = ΔL / L = 250.28 mm - 250 mm / 250 mm = 0.00112
Modulus of elasticity E = 73 GPa = 73 × 10³ MPa where 1 MPa = 1 N/mm²
E = 73 × 10³N/mm²
stress = 73 × 10³N/mm²× 0.00112 = 81.76 N/mm² ( MPa)
b) Factor of safety = maximum allowable stress / induced stress = 140 MPa / 81.76 MPa = 1.71233
Given Information:
Initial temperature of aluminum block = 26.5°C
Heat flux = 4000 w/m²
Time = 2112 seconds
Time = 30 minutes = 30*60 = 1800 seconds
Required Information:
Rise in surface temperature = ?
Answer:
Rise in surface temperature = 8.6 °C after 2112 seconds
Rise in surface temperature = 8 °C after 30 minutes
Explanation:
The surface temperature of the aluminum block is given by

Where q is the heat flux supplied to aluminum block, k is the conductivity of pure aluminum and α is the diffusivity of pure aluminum.
After t = 2112 sec:

The rise in the surface temperature is
Rise = 35.1 - 26.5 = 8.6 °C
Therefore, the surface temperature of the block will rise by 8.6 °C after 2112 seconds.
After t = 30 mins:

The rise in the surface temperature is
Rise = 34.5 - 26.5 = 8 °C
Therefore, the surface temperature of the block will rise by 8 °C after 30 minutes.
Answer: the ripple factor is 0.005
Explanation:
Given the data in the question;
we know that expression of ripple factor is;
r = Vr(pp) / Vdc
where Vr(pp) the peak to peak is ripple voltage ( 100mv = 0.1 V)
and Vdc is the dc value of the filter output voltage ( 20 V)
so we substitute our given values;
r = 0.1 / 20
r = 0.005
Therefore; the ripple factor is 0.005