What is the law of conservation all about?

The plum pudding model of the atom states that ?

If an athlete runs once around a track, back to the starting line, her average velocity is zero. true or false?

In order of decreasing light-transmitting capabilities of materials, which is the correct sequence? a. transparent -> translucent -> opaque b. opaque -> transparent -> translucent c. opaque -> translucent -> transparent d. translucent -> transparent -> opaque