Answer:
No one can see in total darkness. Fortunately, there’s almost always some light available. Even if it’s only dim starlight, that’s enough for your eyes to detect. What’s truly amazing is how little light is required for you to see.
Human eyes have two main features that help us see better in low light: the pupil’s ability to change size, and the eye’s two types of light-sensing cells.
Opening up to let in more light
Your pupils are the black areas at the front of your eyes that let light enter. They look black because the light that reaches them is absorbed inside the eyeball. It’s then converted by your brain into your perceptions of the world.
You’ve probably noticed that pupils can change size in response to light. Outside on a bright sunny day, your pupils become very small. This lets less light into the eye since there’s plenty available
Answer:
The magnitude of the magnetic field is 0.156 T.
Explanation:
Given that,
Speed of a proton, 
Radius of the circular path, r = 0.2 m
When the proton enters in the circular path, the centripetal force is balanced by the magnetic force such that :
q is the charge on proton
Here, 
So, the magnitude of the magnetic field is 0.156 T. Hence, this is the required solution.
Explanation:
The half life is the time taken for a half of a radioactive material or substance to decay to half.
After the passing of the half-life, only half of the original material will remain. Now, let us follow the half-life sequence of this decay;
One half-life
Original: 1000cm
one half life = 500cm
Two half-lifes
Original: 500:
half-life = 250cm
Three half-lifes
Original : 250cm
Half life = 125cm
Four half-lifes
Original: 125cm
Half life = 62.5cm
Five half-lifes
Original: 62.5cm
Half-life = 31.25cm
Six half-lifes
Original: 31.25cm
Half-life = 15.625
learn more:
Half life brainly.com/question/1695370
#learnwithBrainly
