Question 1 of 20 :
2 answers:
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Answer:
the thickness of the soap film is 127.82 nm or 130 nm
Explanation:
Given the data in the question;
n = 1.33
λ = 680 nm = 680 × 10⁻⁹ m
m = 1 and β = 0
When we see the red fringe, its a point of maximum reflection
hence, for interference with a thin soap film, we say;
2 × n × d × cos( β ) = ( m - 0.5) × λ
so we substitute in our given values;
2 × 1.33 × d × cos( 0 ) = ( 1 - 0.5) × ( 680 × 10⁻⁹ )
2.66 × cos( 0 ) × d = 0.5 × ( 680 × 10⁻⁹ )
2.66 × 1 × d = 3.4 × 10⁻⁷
d = ( 3.4 × 10⁻⁷ ) / 2.66
d = 127.82 × 10⁻⁹ m
d = 127.82 nm ≈ 130 nm
Therefore, the thickness of the soap film is 127.82 nm or 130 nm
The average time that it takes for the car to travel the first 0.25m is 2.23 s
The average time that it takes for the car to travel the first 0.25 m is given by:
The average time to travel just between 0.25 m and 0.50 m is 0.90 s
First of all, we need to calculate the time the car takes in each trial to travel between 0.25 m and 0.50 m:
Then, the average time can be calculated as
Given the time taken to travel the second 0.25 m section, the velocity would be 0.28 m/s
The velocity of the car while travelling the second 0.25 m section is equal to the distance covered (0.25 m) divided by the average time (0.90 s):