If you look at faint stars, you can see them more easily on the edges of your vision than if you try to look directly at them. Why is this true?

The retina comprises of rod and cone cells . The rod cells are responsible for black and white vision and require low light levels while the cone cells are responsible for color vision and require good/high light levels for better functioning.

When faint stars are looked at on the edges of the vision it allows more light from faint objects to strike the rod cells which then becomes more visible.

260 miles per hour

explanation:

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if the person is shown to have -90n, then ans is +10n.