Answer:
This band gap also allows semiconductors to convert light into electricity in photovoltaic cells and to emit light as LEDs when made into certain types of diodes. Both these processes rely on the energy absorbed or released by electrons moving between the conduction and valence bands.
Explanation:
On the internet
Answer:
the surface heat-transfer coefficient due to natural convection during the initial cooling period. = 4.93 w/m²k
Explanation:
check attachement for answer explanation
Answer:
F = 0.0022N
Explanation:
Given:
Surface area (A) = 4,000mm² = 0.004m²
Viscosity = µ = 0.55 N.s/m²
u = (5y-0.5y²) mm/s
Assume y = 4
Computation:
F/A = µ(du/dy)
F = µA(du/dy)
F = µA[(d/dy)(5y-0.5y²)]
F = (0.55)(0.004)[(5-1(4))]
F = 0.0022N
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:
ΔQ = 4930.37 BTu
Explanation:
given data
height h = 8ft
Δt = 8 hours
length L = 24 feet
R value = 16.2 hr⋅°F⋅ft² /Btu
inside temperature t1 = 68°F
outside temperature t2 = 16°F
to find out
number of Btu conducted
solution
we get here number of Btu conducted by this expression that s
......................1
here A is area that is = h × L = 8 × 24 = 1492 ft²
put here value we get
solve it we get
ΔQ = 4930.37 BTu
