How long will it take a ball to roll 20 meters along the floor at a speed of 0.4 m/s

How many times did thomas edison mess up the light bulb

If the chemical properties of a substance remain unchanged and appearance or shape of a substance changes it is called a ?

What effects result when there is an impact between earth and an asteroid? check all that apply. a.massive flooding. b.extinction of many life forms.c.major earthquakes change in average global temperature.d. giant dust cloud