The lens of a slide projector has a focal length of +12.0 cm. A slide 12.6 cm to the left of the lens forms the object for the lens. The screen should be placed
a. 25 cm to the left of the lens.
b. 25 cm to the right of the lens.
250 cm to the left of the lens.
d. 250 cm to the right of the lens.
e. 390 cm to the right of the lens.
C.

The path of a satellite orbiting the earth causes it to pass directly over two tracking stations a and b, which are 51 miles apart. when the satellite is on one side of the two stations, the angles of elevation at a and b are measured to be 87 degrees and 84 degrees, respectively. (a) how far is the satellite from station a? (b) how high is the satellite above the ground?