Answer:
r = 41.1 10⁹ m
Explanation:
For this exercise we use the equilibrium condition, that is, we look for the point where the forces are equal
∑ F = 0
F (Earth- probe) - F (Mars- probe) = 0
F (Earth- probe) = F (Mars- probe)
Let's use the equation of universal grace, let's measure the distance from the earth, to have a reference system
the distance from Earth to the probe is R (Earth-probe) = r
the distance from Mars to the probe is R (Mars -probe) = D - r
where D is the distance between Earth and Mars
M_earth (D-r)² = M_Mars r²
(D-r) = r
r ( ) = D
r =
We look for the values in tables
D = 54.6 10⁹ m (minimum)
M_earth = 5.98 10²⁴ kg
M_Marte = 6.42 10²³ kg = 0.642 10²⁴ kg
let's calculate
r = 54.6 10⁹ / (1 + √(0.642/5.98) )
r = 41.1 10⁹ m
Answer:
Wood Resistance = 0.18 m².°C/W
Explanation:
The formula for heat flow in terms of thermal resistance is:
Q/A = ΔT/R
R = AΔT/Q
where,
R = Total Resistance = Resistance of Concrete + Resistance of wood = Resistance of wood + 0.26 m².°C/W
A = Surface Area of Wall = 3.2 m x 4.7 m = 15.04 m²
ΔT = Difference in temperature = 16°C - 2°C = 14°C
Q = Heat Flow = 476 Watt
Therefore,
0.26 m².°C/W + Wood Resistance = (15.04 m²)(14°C)/(476 W)
Wood Resistance = 0.44 m².°C/W - 0.26 m².°C/W
<u>Wood Resistance = 0.18 m².°C/W</u>
Answer:
100nm-280nm
Explanation:
Ultraviolet rays (UV) are part of the electromagnetic spectrum. It goes from 10nm to 400nm wavelengths, they are shorter than visible light, thus it's impossible to see by a human eye, and larger than X-rays (used in many medical applications and harmful when long-exposed).
According to its wavelengths, UV can be divided in different types:
UVA: long wave UV (315nm-400nm)
UVB: medium-wave UV (280nm-315nm)
UVC: short wave UV (100nm-280nm)
Therefore, UVC comprises wavelengths between 10nm and 280nm.
Answer:
Explanation:
According to ohm's law, we know that:
Where,
- Voltage (V) = 2000 Volts
- Current (I) = 200 Amperes
Substituting the values, we get:
→ 2000 = 200 × R
→ 2000/200 = R
→ 10 = R
Hence,
- <u>Required Resistance = 10 </u><u>o</u><u>hm</u>