Answer:
a) I = 1,894 10¹⁰ W / m², b) E = 1.376 10⁵ N / C
Explanation:
a) intensity is defined as energy per unit area per unit time
I = P / A
let's reduce the magnitudes to the SI system
P = 10 mW = 10 10⁻³ W
d = 0.82 μm = 0.82 10⁻⁶ m
the laser area is
A =π r² = π d²/4
A =π (0.82 10⁻⁶)²/4
A = 5.28 10⁻¹³ m²
we calculate
I = 
I = 1,894 10¹⁰ W / m²
b) average intensity and electric field are related
I = E * E
E = √I
E = 
E = 1.376 10⁵ N / C
Explanation:
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Answer:
2019 light bulbs
Explanation:
So the electrical energy consumed by each 59-W light bulb within 7 hours is the product of the power and time duration
E = Pt = 59 * 7 = 413 Wh or 0.413 kWh
If each light bulb consumes 0.413 kWh, then the total number of light bulbs needed to consume 834 kWh would be
834 / 0.413 = 2019 light bulbs
Brass is an alloy, a combination of two metals, and aluminum is a pure metal
Answer:
2795.3 J
Explanation:
distance, d = 28 feet = 8.53 m
Force, F = 80 lb = 356 N
Angle, θ = 23°
Work = F x d x cos θ
W = 356 x 8.53 x cos 23
W = 2795.3 J
Thus, the work done is 2795.3 J.
