Answer:
10.52 m
Explanation:
The power radiated by a body is given by
P = σεAT⁴ where ε = emissivity = 0.97, T = temperature = 30 C + 273 = 303 K, A = surface area of human body = 1.8 m², σ = 5.67 × 10⁻⁴ W/m²K⁴
P = σεAT⁴ = 5.67 × 10⁻⁸ W/m²K⁴ × 0.97 × 1.8 m² × (303)⁴ = 834.45 W
This is the power radiated by the human body.
The intensity I = P/A where A = 4πr² where r = distance from human body.
I = P/4πr²
r = (√P/πI)/2
If the python is able to detect an intensity of 0.60 W/m², with a power of 834.45 W emitted by the human body, the maximum distance r, is thus
r = (√P/πI)/2 = (√834.45/0.60π)/2 = 21.04/2 = 10.52 m
So, the maximum distance at which a python could detect your presence is 10.52 m.
Answer:
4.5 W
Explanation:
Applying,
P = V²/(R₁+R₂).................. Equation 1
Where P = Power, V = Voltage, R₁ and R₂ = values of the two resistor.
From the question,
Given: V = 9.00 V, R₁ = 7.00 Ω, R₂ = 11.00 Ω
Substitute these values into equation 1
P = 9²/(7+11)
P = 81/(18)
P = 4.5 Watt.
Hence the power dessipated by the two resistors is 4.5 watt
