Answer:
Because the light reflects multiple times until it gets to the Cassegrain focus.
Explanation:
The Cassegrain design can be seen in a reflecting telescope. In this type of design the light is collected by a concave mirror, and then intercepted by a secondary convex mirror, and sends it down to a central opening in the primary mirror (concave mirror), in which a detector is placed (Cassegrain focus)
Since, the light is reflected many times due to Cassegrain design, that leads to shorter telescopes.
So power is equal to work over time and work is force times distance, you do 5 times 3 and get 15 dividing by 2 gives us 7.5 W answer c
The electrical equivalent of one horsepower is 746 watts in the International System of Units (SI), and the heat equivalent is 2,545 BTU (British Thermal Units) per hour. Another unit of power is the metric horsepower, which equals 4,500 kilogram-metres per minute (32,549 foot-pounds per minute), or 0.9863 horsepower.
The appropriate response is the rotation. There are most likely no less than 100 billion planets in the Milky Way. The Solar System is situated inside the circle, around 26,000 light-years from the Galactic Center, on the inward edge of one of the winding molded centralizations of gas and tidies called the Orion Arm.
Mechanical advantage of a machine is the ratio of the output force over the input force or M=Fo/Fi. Since M=1, Fi=Fo, or the input force is equal to the output force. This means that to raise the refrigerator that weighs 900 N, we need the same input force of 900 N, or Fo=Fi=900 N.