Q. A wire streches from the top of a vertical pole to a point on level ground 16 feet from the base of the pole. if the wire makes an angle of 62 degrees withe the ground, find the height of the pole and the length of the wire.
Q. Consider a civilization broadcasting a signal with a power of 1.8×104 watts. The Arecibo radio telescope, which is about 300 meters in diameter, could detect this signal if it is coming from as far away as 134 light-years. Suppose instead that the signal is being broadcast from the other side of the Milky Way Galaxy, about 70000 light-years away.
How large a radio telescope would we need to detect this signal? (Hint: Use the inverse square law for light.)