Answer:
0.79
Explanation:
Using Snell's law, we have that:
n(1) * sin θ1 = n(2) * sinθ2
Where n(1) = refractive index of air = 1.0003
θ1 = angle of incidence
n(2) = refractive index of second substance
θ2 = angle of refraction
The angle of reflection through the unknown substance is the same as the angle of incidence of air. This means that θ1 = 32°
=> 1.0003 * sin32 = n(2) * sin42
n(2) = (1.0003 * sin32) / sin42
n(2) = 0.79
C. spokesperson are respected members of the scientific community
The power dissipated by the LED is 20 Watts and the work done for 1 hour 15 minutes is 56.25 kJ.
<h3>What is electrical power?</h3>
Electrical power is the rate at which electrical work is done.
- Electrical power = voltage × current
The LED is 75% efficient means that 75% of power dissipated by the LED is converted to light.
Total power dissipated = 5 × 2.5 = 12.5 Watts
- Work done = power × time (in seconds)
Work done = 12.5 × (1 × 3600 + 15 × 60)
Work done = 56250 J = 56.25 kJ
Therefore, the power dissipated by the LED is 20 Watts and the work done for 1 hour 15 minutes is 56.25 kJ.
Learn more about electrical power and work done at: brainly.com/question/23901751
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