Answer:
η₁ = 2.6
Explanation:
Here, we will use snell's law to calculate the refractive of the substance:
where,
η₁ = refractive index of first substance = ?
η₂ = refractive index of second substance = 1.5
θ₁ = angle of incidence = 30°
θ₂ = angle of refraction = 60°
Therefore,
<u>η₁ = 2.6</u>
The distance travelled by the object during the first 4 seconds is 80 m
<h3>Definition of speed </h3>Speed is defined as the distance travelled per unit time. Mathematically, it can be expressed as:
Speed = distance / time
With the above formula, we can obtain the distance travelled by the object in the first 4 seconds.
<h3>How to determine the distance travelled </h3>Speed = distance / time
20 = distance / 4
Cross multiply
Distance = 20 × 4
Distance = 80 m
Complete question:
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