Answer: a) -3.5m b) 0.22man
Explanation:
a) A near sighted person is a person that can only see near objects clearly but not far objects.
According to the lens formula
1/u+1/v = 1/f
where u = object distance (distance between the object and the lens)
v = image distance (distance between the image and the lens)
f = focal length of the lens
Given u= infinity v = 3.5m f= ?
1/f = 1/infinity +1/3.5
Since the lens used for correcting near sighted person is concave lens therefore the image distance is negative due to virtual image produced by the lens.
We then have 1/f1 = 1/infinity -1/3.5
f1 = -3.5m
b) A far sighted person is a person that can only see far objects clearly but not near objects.
According to the lens formula
1/u+1/v = 1/f
Given u= 0.35m v = 0.6m f2= ?
1/f2 = 1/0.35 + 1/0.6
Since the lens used for correcting far sighted person is convex lens therefore the image distance is positive due to mostly real image produced by the lens (reason why the image distance is positive.
f2 = 0.22m
Answer:
b = 2.22 cm
Explanation:
The laser hits a point where the origin of the coordinate system is to carry out the measurements. When the ray enters the glass the angle of refraction is given by the equation
n₁ sin θ₁ = n₂ sin θ₂
where n₁ is the index of refraction of air n₁ = 1 and n₂ is the index of refraction of glass n₂ = 1.6
sin θ₂ = n₁ /n₂ sin θ₁
sin θ₂ = 1 / 1.6 sin 36
sin θ₂ = 0.367
θ₂ = sin⁻¹ 0.367
θ₂ = 21.6º
with this angle and trigonometry we can find the distance x that the ray advances before reaching the bottom of the glass plate
tan 21.6 = x / d
where d is the thickness of the glass d = 2.8 cm
x = d tan 21.6
x = 2.8 tan 21.6
x = 1.11 cm
as in the second surface it has a process of reflection the angle of reflection is equal to the angle of incidence θ_reflected = 21.6º, therefore to return to the upper surface recreate the same distance, therefore the total distance is
b = 2x
b = 2 1.11
b = 2.22 cm
1 newton is the force that accelerates 1 kilogram of mass at the rate of 1 meter per second^2. / / / 1N = 1 kg-m / sec^2 .
