Can someone please help me with these questions and explain the principles for these questions? I don't really understand the physics behind them...
1. A red ball is resting on a blue carpet. If white light is shone on them and they are viewed through a green filter, the observer will see which of the following?
a) A black ball on a black carpet
b) A red ball on a blue carpet
c) A green ball on a green carpet
d) A yellow ball on a cyan carpet
e) A magenta ball on a cyan carpet
2. Suppose that you are standing on a river bank with a fish in sight in the water. If you want to catch the fish with a spear, should you aim directly at the fish, in front of the fish or behind the fish? Explain your answer using a diagram. (Can someone explain this without the use of a diagram? I'm a bit confused...)
Question 2 also has an equation attached to it, but I'm not sure it helps...
n (refractive index) = real depth/apparent depth
Any help will be greatly appreciated!!!
1. A red ball is resting on a blue carpet. If white light is shone on them and they are viewed through a green filter, the observer will see which of the following?
a) A black ball on a black carpet
b) A red ball on a blue carpet
c) A green ball on a green carpet
d) A yellow ball on a cyan carpet
e) A magenta ball on a cyan carpet
2. Suppose that you are standing on a river bank with a fish in sight in the water. If you want to catch the fish with a spear, should you aim directly at the fish, in front of the fish or behind the fish? Explain your answer using a diagram. (Can someone explain this without the use of a diagram? I'm a bit confused...)
Question 2 also has an equation attached to it, but I'm not sure it helps...
n (refractive index) = real depth/apparent depth
Any help will be greatly appreciated!!!
-
Question 1
Assuming all colours are absolute, i.e. fully saturated primary colours, the answer will be a) A black ball on a black carpet. The red ball reflects only red light and the blue carpet reflects only blue light, neither of which can pass through the green filter, which only permits green light to pass.
Question 2
You should aim in front of the image. The refractive index of water will make the fish appear to be swimming at a depth that is more shallow than it is actually swimming.
The formula (which is subtly incorrect and probably a simplification of Snell's law for illustrative purposes) can be re-arranged to more suit the context of the question with:
apparent depth = real depth / refractive index.
Assuming all colours are absolute, i.e. fully saturated primary colours, the answer will be a) A black ball on a black carpet. The red ball reflects only red light and the blue carpet reflects only blue light, neither of which can pass through the green filter, which only permits green light to pass.
Question 2
You should aim in front of the image. The refractive index of water will make the fish appear to be swimming at a depth that is more shallow than it is actually swimming.
The formula (which is subtly incorrect and probably a simplification of Snell's law for illustrative purposes) can be re-arranged to more suit the context of the question with:
apparent depth = real depth / refractive index.