Which is an example of an open system? a. the carbon cycle b. the water cycle c. the universe d. a food web

(a) assume the equation x = at^3 + bt describes the motion of a particular object, with x having the dimension of length and t having the dimension of time. determine the dimensions of the constants a and b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.) (b) determine the dimensions of the derivative dx/dt = 3at^2 + b. (use the following as necessary: l and t, where l is the unit of length and t is the unit of time.)

Lightning is an example of what phenomenon? a release of a large amount of energyan absorption of a large amount of energya natural electric circuita natural electric current

What happens when a rubber rod is rubbed with a piece of fur?