Why does an object in motion stay in motion unless acted on by an unbalanced force? a) because forces are what stop and start motion b) because balanced forces cannot exist in nature c) because motion is the inherent state of all matter d) because motion, once begun, continues to accelerate

Which statement best describes the relationship between period and frequency of light waves? a) in wave b the period increases and the frequency decreases from wave a. b) in wave a the period increases and the frequency decreases from wave b. c) in wave b the period is shorter and the frequency is greater than in wave a. d) in wave a the period is shorter and the frequency is greater than in wave b.

Anthracite is so hard and pure it is also referred to as a renewable resource metamorphic rock hot bituminous coal dirty fuel

The identities of substances are the same before and after which type of change