Ilona and Olivia observe a virtual image formed by an object placed a distance in front of a convex lens of focal length f. They argue about where to place a concave lens of focal length ?f to have a virtual image at the same location relative to the lens that they had with the convex lens. Ilona says that the object should also be placed a distance

/> in front of the concave lens. Olivia says that this won't work. Which one, if either, is correct, and why?

A.

Ilona, because concave and convex lenses produce virtual images at equal image distances when the object distances are equal.

B.

Ilona, because bothd₀ andd_iare negative for a concave lens.

C.

Olivia, because both d₀ and d_i are positive for a concave lens.

D.

Olivia, because if d_i = , then d₀ was d₀ = ?.

E.

Olivia, because if d_i = ?f, then d₀ was d₀ = ?.

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Answer: E

Physics & Space Science

Which of the following statements about electromagnetic waves in a vacuum are true? (There could be more than one correct choice.)

A) The electric field carries more energy than the magnetic field. B) The electric and magnetic fields have equal amplitudes. C) The electric field carries the same mount of energy as the magnetic field. D) The frequency of the magnetic field is the same as the frequency of the electric field. E) The frequency of the electric field is higher than the frequency of the magnetic field.

Most of the angular momentum of the solar system is found in the ________

Fill in the blank(s) with correct word

The largest asteroid, and probably the only one to be a spherical "world," is

A) Ceres. B) Ida. C) Vesta. D) Gaspra. E) Eros.

According to current evidence, Pluto is best explained as ________

A) an escaped moon of Jupiter or Saturn B) a large member of the Kuiper belt C) a terrestrial planet that is surprisingly far from the Sun D) a very small jovian planet