Final answer:
The position of the image formed by the glass rod can be determined using the lens formula. When the object is placed infinitely far from the left end of the rod, the image is formed at the focal point. When the object is placed 18.0 cm to the left of the rod, the image is formed at a distance of 5.18 cm from the left end. And when the object is placed 4.00 cm from the left end of the rod, the image is formed at a distance of 1.80 cm.
Step-by-step explanation:
To determine the position of the image formed by the glass rod, we can use the lens formula:
1/f = (n - 1) * (1/r1 - 1/r2)
Where f is the focal length, n is the refractive index, r1 is the radius of curvature of the left surface, and r2 is the radius of curvature of the right surface.
A) When the object is placed infinitely far from the left end of the rod, the image is formed at the focal point, which is half the focal length.
sb = f/2 = (1.60 - 1) * (1/4.00 - 1/inf)
sb = 0.50 cm
B) When the object is placed 18.0 cm to the left of the rod, we can use the lens formula to calculate the position of the image:
sb = f - so = (1.60 - 1) * (1/4.00 - 1/18.00)
sb = 5.18 cm
C) When the object is placed 4.00 cm from the left end of the rod, we can again use the lens formula to find the position of the image:
sb = f - so = (1.60 - 1) * (1/4.00 - 1/(8.00 - 4.00))
sb = 1.80 cm