Answer:
200 nm is the thinnest film that produces a strong reflection for green light with a wavelength of 500 nm
Explanation:
If two reflected waves interfere constructively ,strong reflection is produced. Two reflected waves will experience a phase change
For constructive interference

for thinnest film m=1
refractive index should be taken for film n=1.25
thickness of the thinnest film is

20 centimeters. 100 centimeters in a meter. 100/5= 20
Answer:
F = 5226.6 N
Explanation:
To solve a lever, the rotational equilibrium relation must be used.
We place the reference system on the fulcrum (pivot point) and assume that the positive direction is counterclockwise
F d₁ = W d₂
where F is the applied force, W is the weight to be lifted, d₁ and d₂ are the distances from the fulcrum.
In this case the length of the lever is L = 5m, t the distance desired by the fulcrum from the weight to be lifted is
d₂ = 200 cm = 2 m
therefore the distance to the applied force is
d₁ = L -d₂
d₁ = 5 -2
d₁= 3m
we clear from the equation
F = W d₂ / d₁
W = m g
F = m g d₂ / d₁
we calculate
F = 800 9.8 2/3
F = 5226.6 N
Answer:
2.52 m/s
Explanation:
When the man takes a step, his foot is stationary while his body revolves around it. At the point when his body is directly above his foot, there will be no normal force at his maximum speed.
Sum of the forces in the radial direction:
∑F = ma
mg = m v² / r
g = v² / r
v = √(gr)
Given that r = 0.650 m:
v = √(9.8 m/s² × 0.650 m)
v = 2.52 m/s
Explanation:
It is given that,
Average power per unit mass generated by Lance, 

(a) Distance to cover race, 
Average speed of the person, v = 11 m/s
If t is the time taken to cover the race.


t = 14545.46 s
Let W is the work done. The relation between the work done and the power is given by :



W = 7090911.75 J
(b) Since, 
So, in 7090911.75 J, 
W = 1694.01 J
Hence, this is the required solution.