Numbers often have units. We can prepare these numbers for conversion by writing them as fractions.

What color would an object that reflects green and blue light appear to be in white light? a. blue b. cyan c. magenta d. black

Describe the path of a ray that approaches a mirror parallel to the principal axis.

Ahot-air balloonist, rising vertically with a constant speed of 5.00 m/s releases a sandbag at the instant the balloon is 40.0 m above the ground. after it is released, the sandbag encounters no appreciable air drag. compute the velocity of the sandbag at 0.250 s after its release.