A tennis ball is thrown vertically upward with an initial velocity of +8.0 m/s.
a. What will the ball's speed be when it returns to its
starting point?
b. How long will the ball take to reach its starting
point?

Ascientist studies a model of a widely accepted theory about the universe. the model would most likely the scientist to understand a theory which cannot be observed prove that the theory would not change in the future demonstrate how the theory can be changed into a law prove that all other theories about the universe are incorrect