Final answer:
The magnification of a mountain viewed through a magnifying glass with a focal length of 10 cm is 3.5 times.
Step-by-step explanation:
When viewing a mountain with a magnifying glass, the magnification (M) provided is related to the focal length (f) of the magnifying glass and the distance where the eye is placed (do) from the glass. Since the mountain is very far away, we can approximate the object distance to be at infinity. This means the magnified image forms at the near point of the eye, which for a person with normal vision is about 25 cm from the eye. The magnification of a magnifying glass is given by the equation M = 1 + (de / f), where de is the near point normal distance (25 cm in this case) and f is the focal length of the lens.
Using the focal length f = 10 cm, the magnification would be M = 1 + (25 cm / 10 cm) = 1 + 2.5 = 3.5. Therefore, the magnification of the mountain when viewed through a magnifying glass with a focal length of 10 cm would be 3.5 times.