So whenever it won't work, try to find a new pic because your current one is too small / big. Type in the size, for example, 10x10 cool backgrounds, and pick one. You can do any size and any background so long as it fits. Also don't multiply 10x10 whenever you're dealing with backgrounds.
In order to describe motion along a straight line, you must state the speed and direction of the motion. Those two quantities, together, comprise what's known as "velocity".
a ray of light is incident towards a plane mirror at an angles of 30degrees with the mirror surface. what will be the angles of reflection is 60degree.
