Suppose that a substance in a beaker is heated over a burner in a science lab. Which observation would most likely indicate that a chemical change has occurred in the substance?

The volume v and paper surface area a of a conical paper cup are given by where r is the radius of the base of the cone and h is the height of the cone. a. by eliminating h, obtain the expression for a as a function of r and v. b. create a user-de ned function that accepts r as the only argument and computes a for a given value of v. declare v to be global within the function. c. for v ! 10 in.3 , use the function with the fminbnd function to compute the value of r that minimizes the area a. what is the corresponding value of the height h? investigate the sensitivity of the solution by plotting v versus r. how much can r vary about its optimal value before the area increases 10 percent above its minimum value?

*! 20 points! *jeff wants to create a website with interactive and dynamic content. which programming language will he use? a. dhtml b. html c. css d. javascript

What percentage of teens plays video games? a.97% b.100% c.74% d.50%