Answer: LED have the lowest cost of operation.
Explanation:
If we ignore the initial procurement cost of the items the operational cost of any device consuming electricity is given by

Among the three item's LED consumes the lowest power to give the same level of brightness as compared to the other 2 item's thus LED's shall have the lowest operational cost.
Answer:
The answer is below
Explanation:
Given that:
Diameter (D) = 0.03 mm = 0.00003 m, length (L) = 2.4 mm = 0.0024 m, longitudinal tensile strength
, Fracture strength

a) The critical length (
) is given by:

The critical length (4.5 mm) is greater than the given length, hence th composite can be produced.
b) The volume fraction (Vf) is gotten from the formula:

Answer:
Explanation:
Given conditions
1)The stress on the blade is 100 MPa
2)The yield strength of the blade is 175 MPa
3)The Young’s modulus for the blade is 50 GPa
4)The strain contributed by the primary creep regime (not including the initial elastic strain) was 0.25 % or 0.0025 strain, and this strain was realized in the first 4 hours.
5)The temperature of the blade is 800°C.
6)The formula for the creep rate in the steady-state regime is dε /dt = 1 x 10-5 σ4 exp (-2 eV/kT)
where: dε /dt is in cm/cm-hr σ is in MPa T is in Kelvink = 8.62 x 10-5 eV/K
Young Modulus, E = Stress,
/Strain, ∈
initial Strain, 


creep rate in the steady state


but Tinitial = 0


solving the above equation,
we get
Tfinal = 2459.82 hr
Answer:
Explanation:
A woman walks due west on the deck of a ship at 3 miyh.The ship is moving north at a speed of 22 miyh.Find the speed and direction of the woman relative to the surface of the water.