A refracting telescope has an objective lens of diameter 360 mm360\text{ mm}360 mm and a focal length of 5.40 m5.40\text{ m}5.40 m.
Calculate the wavelength of light for which this telescope has a minimum angular resolution of 1.5×10−6 rad1.5 \times 10^{-6}\text{ rad}1.5×10−6 rad.
The telescope is used to observe two point objects which subtend an angle of 1.5×10−6 rad1.5 \times 10^{-6}\text{ rad}1.5×10−6 rad at the unaided eye. The typical human eye has a minimum angular resolution of approximately 3.0×10−4 rad3.0 \times 10^{-4}\text{ rad}3.0×10−4 rad. Calculate the focal length of the eyepiece lens so that an observer can just resolve the two objects when observing them through this telescope.
The asteroid Bennu has a diameter of 490 m490\text{ m}490 m. At its closest approach to Earth, its distance from the observer is 4.2×104 km4.2 \times 10^4\text{ km}4.2×104 km. The telescope is used to view Bennu using the eyepiece calculated in part 2. Deduce whether this telescope is suitable to obtain a detailed view of Bennu. Support your answer with a calculation.
