1. Do you remember my demonstration of radiative transfer of thermal energy? I shone a beam of light from a lamp onto a "weathervane-like" contraption and instantly, the vanes began revolving as if by magic. I explained that the hot lamp had sent waves of energy to the vanes penetrating through the vacuum in the bulb where the vanes were housed. It was this radiative energy that caused the conditions for the vanes to move. I should also have stated that all objects send out radiative energy and that if I had placed the contraption in bright sunlight the vanes would have moved too. The natural question then arises as to why the lamp and the sun can achieve that but that we who are also emitting radiative energy cannot. For a half (1/2) course point, give me the answer to that question with a full explanation.
2. Explain through physical concepts why the following are "words of wisdom"
3. You and a friend are watching a pool-shark showing off his prowess at billiards. In one demonstration, the pool-shark placed two billiard balls, one red and the other white, near each other on the table, then fires off the red ball so that it strikes one side of the table (A), then an adjacent second side (B), followed by the next adjacent third side (C) before colliding with the white ball. Your friend says she knows how she can do the same trick, at least in theory. She picks up a piece of paper, and then sketches a rectangle to represent the billiard table. She asks you to insert two small circles to represent the balls anywhere on the table. Taking the paper back from you and using a pencil and a ruler, she then draws the "complete trajectory of the red ball" as she would launch it so as to repeat the pool-shark's feat. If the drawing below is what you handed your friend, can you repeat what she did and show the trajectory she drew?
