An object is located 6.0 cm from a plane mirror. If the plane mirror is replaced with a concave mirror, the resulting image is 8.0 cm farther behind the mirror. Assuming that the object is located between the focal point and the concave mirror, what is the focal length of the concave mirror?

An object is located inside the focal point of a concave mirror. Will the image of the object be nearer or farther from the observer than the object itself? Explain.

Can the element iron $(\mathrm{Fe})$ be changed to gold ( $\mathrm{Au})$ by heating it to a high enough temperature? Explain.

Do light waves of different colors all travel at the same speed in glass? Explain

A uniform magnetic field is directed horizontally toward the north, and a positive charge is moving west through this field. Is there a magnetic force on this charge, and if so, in what direction? Explain.

In what respects is the force between two magnetic poles similar to the force between two charged particles? Explain.

The amplitude of a transverse wave on a string is 4.5 cm. The ratio of the maximum particle speed to the speed of the wave is 3. 1. What is the wavelength (in cm) of the wave?

Two coils of wire are identical except that coil A has twice as many turns of wire as coil B. If a magnetic field increases with time at the same rate through both coils, which coil (if either) has the larger induced voltage? Explain.

Suppose that light rays approach a negative lens so that they are converging toward the focal point on the far side of the lens. Will these rays be diverging when they leave the lens? Explain

A light ray traveling in glass for which the critical angle is $42^{\circ}$ strikes a surface between the glass and air at an angle of $45^{\circ}$ to the surface normal. Is this ray refracted into the air at this surface? Explain.

Is it possible to produce an angular magnification of an object by simply bringing the object closer to your eye? Explain.

When a battery is being used in a circuit, will the voltage across its terminals be less than that measured when there is no current being drawn from the battery? Explain

A double image of a dot is seen when viewing the dot through a calcite crystal. Is there any difference in the polarization of the light associated with these two images? Explain

When a convex mirror is used as a side-view mirror on an automobile, where is the image located? Why does printing on the mirror warn you that vehicles may be closer than they appear to be when viewed in the mirror? Explain.