It is round or say spherical to widen the range of photography and it is designed to focus the image as the ray are coming from infinity so !!
I am not an expert of camera but ya it is the main theme !!
Answer:
When the velocity doesn't change its direction
Explanation:
Since velocity vector has 2 components: direction and magnitude, and speed is the velocity's magnitude. So if the velocity doesn't change its direction, we essentially use its magnitude, aka speed, to calculate the rate of change for acceleration.
It had a gravitational force that acts so that it pulls Earth in an orbital, which explains temperature variations throughout the years.
