Answer:
a)6.34 x W/m²
b)1.37 x W/m²
c) see explanation.
Explanation:
a)The relation of intensity'I' of the radiation and area 'A' is given by:
I= P/A
where P= power of sunlight i.e 3.9 x J
and the area of the sun is given by,
A= 4π => 4π
A=6.15 x m²
= 3.9 x / 6.15 x =><u> 6.34 x </u><u>W/m²</u>
b) First determine the are of the sphere in order to determine intensity at the surface of the virtual space
A= 4π
Now R= 1.5 x m
A= 4π x 1.5 x =>2.83 x m²
The power that each square meter of Earths surface receives
= 3.9 x /2.83 x =><u>1.37 x </u><u> W/m²</u>
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c) in part (b), by assuming the shape of the wavefront of the light emitted by the Sun is a spherical shape so each point has the same distance from the source i.e sun on the wavefront.
Answer:
a) Maximum altitude of the projectile,
b) v = 10885.7 m/s
Explanation:
a) Mass of the earth,
Mass of the projectile =
Launch speed, v = 2.31 * 10³ m/s
Earth radius, r = 6.36 ✕ 10⁶ m
Workdone by the projectile against gravity
...............(1)
Kinetic energy of the projectile:
...................(2)
Equating (1) and (2) based on the law of energy conservation
b) Smallest required change in the satellite speed
Altitude, h = 352 km = 352000 m
Earth radius, r = 6.38 * 10⁶ m
v = 10885.7 m/s
Answer:
Temperature of water leaving the radiator = 160°F
Explanation:
Heat released = (ṁcΔT)
Heat released = 20000 btu/hr = 5861.42 W
ṁ = mass flowrate = density × volumetric flow rate
Volumetric flowrate = 2 gallons/min = 0.000126 m³/s; density of water = 1000 kg/m³
ṁ = 1000 × 0.000126 = 0.126 kg/s
c = specific heat capacity for water = 4200 J/kg.K
H = ṁcΔT = 5861.42
ΔT = 5861.42/(0.126 × 4200) = 11.08 K = 11.08°C
And in change in temperature terms,
10°C= 18°F
11.08°C = 11.08 × 18/10 = 20°F
ΔT = T₁ - T₂
20 = 180 - T₂
T₂ = 160°F
Hey there!
<span>Which statement best summarizes Gregor Mendel’s contribution to science?
Mendel is considered the "father of genetics". He did NOT increse the number of peas </span>
<span>produced by a single plant using cross-breeding techniques, discover grean peas and yellow peas, or invent the green pea by cross-breeding thousands of pea plants.
This means your answer is option D.
Hope this helps
Have a great day (:
</span>
Back emf is 85.9 V.
<u>Explanation:</u>
Given-
Resistance, R = 3.75Ω
Current, I = 9.1 A
Supply Voltage, V = 120 V
Back emf = ?
Assumption - There is no effects of inductance.
A motor will have a back emf that opposes the supply voltage, as the motor speeds up the back emf increases and has the effect that the difference between the supply voltage and the back emf is what causes the current to flow through the armature resistance.
So if 9.1 A flows through the resistance of 3.75Ω then by Ohms law,
The voltage across the resistance would be
v = I x R
= 9.1 x 3.75
= 34.125 volts
We know,
supply voltage = back emf + voltage across the resistance
By plugging in the values,
120 V = back emf + 34.125 V
Back emf = 120 - 34.125
= 85.9 Volts
Therefore, back emf is 85.9 V.