Aball is thrown from the top of a building. at time t (in seconds), its height (in feet) follows the path s(t) = -3t2 + 24t + 60.
a. when does it hit the ground?
b. what was its acceleration at time t = 1 ?

What are the necessary conditions for fusion?

Select all the correct answers. which three statements about electromagnetic radiation are true?

The amount of heat required to change liquid water to vapor at its boiling temperature is 2256 kj/kg. the amount of heat required to change liquid mercury to its vapor state at its boiling temperature is 295 kj/kg. one kg of each substance is currently at its boiling point. how will the amount of thermal energy required to change each substance from a liquid to a gas differ?