Answer:
Iris
Explanation:
The iris seems to be the illuminated portion of the eyes which really covers the pupil. It controls the amount of light reaching the eye. The lens is indeed a translucent layer of the retina that serves to concentrate light and objects on the lens.
D. The direction of the force is toward the center of the object's circular path.
Answer:
Time, I believe. Pretty sure it's time lol
Answer:

Explanation:
As we know that


also we know that

it is given as


also we can find the magnitude of two vectors as


similarly we have


now we know the formula of dot product as




Answer:
The value is 
Explanation:
From the question we are told that
The time taken to travel to the planet from earth is 
The time to be spent on the ship is
Generally speed can be obtained using the mathematical relation represented below

The 2 in the equation show that the trip is a round trip i.e going and coming back
=> 
=> 