Answer:
Explanation:
The problem is based on interference in thin films
refractive index of water is more than given oil so there will be phase change of π at upper and lower layer of the film .
a )
for constructive interference , the condition is
2μt = nλ where t is thickness of layer , μ is refractive index , λ is wavelength and n is order of the fringe
Putting the values
2 x 1.27 t = n x 640
2 x 1.27 t = 640 ( for minimum thickness n = 1 )
t = 252 nm .
b )
2 x 1.27 t = m₁ λ₁
for destructive interference
2μt = (2m₂+1)λ₂/2
2 x 1.27 t =(2m₂+1)λ₂/2
m₁ λ₁ = (2m₂+1)λ₂/2
2m₁λ₁ = (2m₂+1)λ₂
2m₁ / (2m₂+1) = λ₂ / λ₁
2m₁ / (2m₂+1) = 548/ 640
2m₁ / (2m₂+1) = .85625
2m₁ = .85625 (2m₂+1)
This is the required relation between m₁ and m₂
Answer:
A) How much work does the Pepsi do on the bullet = 0.0625J
B) At what velocity does the Pepsi hit the floor = 7.67m/s
Explanation:
- Given mass of bullet = 5g
- initial velocity = 500 m/sec
From work done = Force X Distance
Workdone ; m(v - u )/t
A) The work done by the Pepsi is equal to the change in kinetic energy while in the Pepsi:
- but The work done by the container wall on the bullet is equal to the change in kinetic energy on either side of the wall: W = change in kinetic energy = 1/2 mv²
= 1/2 X 0.005 x 500² - 1/2 X 0.055 x 5²
= 624.94J
- Therefore ; The work done by the Pepsi is equal to the change in kinetic energy while in the Pepsi = W = change in KE = 0.0625 - 0 = 0.0625J
B) At what velocity does the Pepsi hit the floor?
- From conservation of energy principle; PE = KE
Answer:
The Light We See
Visible light includes all the wavelengths of light that the human eye can detect. It allows us to see objects in the world around us. Without visible light, we would only be able to sense most objects by sound, touch, or smell. Like humans, most other organisms also depend on visible light, either directly or indirectly. Many animals—including predators of jellyfish—use visible light to see. Plants and certain other organisms use visible light to make food in the process of photosynthesis. Without this food, most other organisms would not be able to survive.
Q: Do you think that some animals might be able to see light that isn’t visible to humans?
A: Some animals can see light in the infrared or ultraviolet range of wavelengths. For example, mosquitoes can see infrared light, which is emitted by warm objects. By seeing infrared light, mosquitoes can tell where the warmest, blood-rich areas of the body are located.
Incandescence
Most of the visible light on Earth comes from the sun. The sun and other stars produce light because they are so hot. They glow with light due to their extremely high temperatures. This way of producing light is called incandescence. Incandescent light bulbs also produce light in this way. When electric current passes through a wire filament inside an incandescent bulb, the wire gets so hot that it glows
