Answer:
21.5°
Explanation:
Given,
Refractive index of water, n₁ = 1.33
Refractive index of polystyrene, n₂ = 1.49
Angle of reflection = ?
Angle of refraction = 19.1°
Using Snell's law
n₁ sin θ₁ = n₂ sin θ₂
1.33 x sin θ₁ = 1.49 x sin 19.1°
sin θ₁ = 0.366
θ₁ = 21.5°
According to law of reflection angle of incidence is equal to angle of reflection.
Angle of reflection = 21.5°
By tightening a string you are actually putting more stress on the string you are giving it a new frequency that isn't natural.
Hope this helps
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Answer:
true
Explanation:
Friction occurs because no surface is perfectly smooth. Rougher surfaces have more friction between them. Heavier objects also have more friction because they press together with greater force. Friction produces heat because it causes the molecules on rubbing surfaces to move faster and have more energy.
Answer:
80 ft/s
Explanation:
Use III equation of motion
V^2 = U^2 + 2g h
Here, U = 0, g = 32 ft/s^2, h = 100 ft
V^2 = 0 + 2 × 32 ×100
V^2 = 6400
V = 80 ft/s
