Answer:
(A) Q = 321.1C (B) I = 42.8A
Explanation:
(a)Given I = 55A−(0.65A/s2)t²
I = dQ/dt
dQ = I×dt
To get an expression for Q we integrate with respect to t.
So Q = ∫I×dt =∫[55−(0.65)t²]dt
Q = [55t – 0.65/3×t³]
Q between t=0 and t= 7.5s
Q = [55×(7.5 – 0) – 0.65/3(7.5³– 0³)]
Q = 321.1C
(b) For a constant current I in the same time interval
I = Q/t = 321.1/7.5 = 42.8A.
W work
F force
s distance
If F = constant:
W₁ = F·s
If you triple the force and the distance:
W₂ = 3F · 3s = 9 F·s = 9 W₁
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The index of refraction of the unknown material in which a ray of light is incident at 35° and refracted at 23° is 2.03
<h3>Snell's law</h3>
index of refraction (n) = Sine i / Sine r
n = Sine i / Sine r
Where
- i is the angle of incidence
- r is the angle of refraction
<h3>How to determine the refractive index </h3>
From the question given above, the following data were obtained:
- Index of refraction of oil (nₒ) = 1.38
- Angle of incidence (i) = 35°
- Angle of refraction (r) = 23°
- Index of refraction of unknown material (nᵣ) =?
nₒSine i = nᵣSine r
1.38 × Sine 35 = nᵣ × Sine 23
Divide both side by Sine 23
nᵣ = (1.38 × Sine 35) / Sine 23
nᵣ = 2.03
Thus, the index of refraction of the unknown material is 2.03
Learn more about Snell's law:
brainly.com/question/25758484
Answer:
40 MJ (D)
Explanation:
Quantity of heat (Qh) = 100 MJ
temperature of steam (Th) = 450°c = 450 + 273 = 723 K
emperature of water (TI) = 20 °c = 20 + 273 = 293 k
efficiency = (Qh-Qi)/Qh = (Th-Ti)/Th
- Qi= 0.5947 x 
- (0.5947 x ) = Qi
Qi = 40.5 MJ equivalent to 40 MJ (D)
