Which statement about dwarf planets is true?
a. pluto was the first dwarf planet to be discovered.
b. all dwarf planets likely contain a mixture of rock and ice.
c. dwarf planets lie beyond the outer planets

"Pluto was the first dwarf planet to be discovered" is the one statement among the following choices given in the question that is true about dwarf planets. The correct option among all the options that are given in the question is the first option or option "a". Pluto was classified as a planet at first but in the year 1930 it was classified as a dwarf planet.

Velocity=total displacement/timefrom house to store is 500 from store to neighbor is 200 therefore total displacement=500+200=700metrestherefore,700metres/910seconds=0.8metres per second

Planck decided to assume that atoms could only vibrate at certain frequencies that were whole numbers eg 2f, 3f and so on. others used to think that atoms vibrate continuously