Which scenario is an example of a physical change? Wood is burned in a campfire and is turned into ash and smoke.
A piece of metal is left in the rain and forms rust.
Lead is melted into a liquid to form pellets.
Yeast turns sugar into energy, water, and carbon dioxide gas.

Calculate the capacitance of a system that stores 2.0 x 10^-10c of charge at 100.0 v. use c=q/v. a. 2.0 x 10^-12 f b. 2.0 x 10^-8 f c. 5.0 x 10^11 f d. 5.0 x 10^7 f

If a rock is thrown upward on the planet mars with a velocity of 12 m/s, its height (in meters) after t seconds is given by h = 12t − 1.86t2. (a) find the velocity of the rock after two seconds. m/s (b) find the velocity of the rock when t = a. 12−3.72a m/s (c) when will the rock hit the surface? (round your answer to one decimal place.) t = s (d) with what velocity will the rock hit the surface? m/s

Frank just graduated from eighth grade. assuming exactly four years from now he will graduate from high school how many seconds does he have until his high school graduation