Answer:
Explanation:
You can ignore how high the window actually is, unless the calculator falls further. You just want to use the formula v_f = v_i + at Let em know if that doesn't help and I can work you through it.
To check the distance use y = v_i*t + .5at^2. Would just plug in 0*1.8 + .5(-9.8)1.8^2 = -15.876, so it doesn't fall more than 20.7 m so indeed, you don't have to worry about that.
Again, let me know if you need further help.
D, single replacement and exothermic. Single replacement because chlorine switches over to magnesium, exothermic because the reaction releases energy, evidenced by the test tube getting hot and the bark that's heard.
Answer:
The Astronomical Unit (AU) is approximately , the ratio of Astronomical Units per mile is .
Explanation:
The distance from the Earth to the Sun is approximately , then the Astronomical Unit (AU) is approximately . The ratio can be described by the quantity of miles per Astronomical Unit, then we define:
.
Burning a substance means that you have damaged it, and this is irreversible, which is a quality that chemical changes have. Burning a substance also changes the substance into ash, which makes it a chemical change as the substance has been formed into something else.
I hope this helps!