Answer:
I think they use it at night because they want to avoid involving themselves in road accident while crossing the street. When there are reflective strips on their clothes, drivers do notice them even at far ends of the street since the strips will reflect the rays from the car lights to the driver,hence, the driver notifies that there is a pedestrian crossing and therefore slows down.
Before you start working on any motion problem, YOU decide which direction you're going to call 'positive'. Everybody almost always calls UP positive, and the acceleration of gravity points down, so it winds up negative. But you could just as well call DOWN the positive direction. Then, the cannonball is fired with a negative vertical speed, and the acceleration of gravity eventually robs all of its negative speed, and makes it start falling in the positive direction. The whole thing is your choice.
<span>The manipulation of natural sounds via the medium of magnetic tape is called "</span>Musique concrete".
Musique concrete refers to an experimental method of melodic composition utilizing recorded sounds as crude material. The strategy was created around 1948 by the French composer Pierre Schaeffer and his partners at the Studio d'Essai ("Experimental Studio") of the French radio framework. The major guideline of musique concrète lies in the collection of different regular sounds recorded on tape (or, initially, on plates) to deliver a montage of sound.
