A police car is located 70 feet to the side of a straight road. A red car is driving along the road in the direction of the police car and is 160 feet up the road from the location of the police car. The police radar reads that the distance between the police car and the red car is decreasing at a rate of 85 feet per second. How fast is the red car actually traveling along the road

The frequency of vibrations of a vibrating violin string is given by f = 1 2l t ρ where l is the length of the string, t is its tension, and ρ is its linear density.† (a) find the rate of change of the frequency with respect to the following. (i) the length (when t and ρ are constant) (ii) the tension (when l and ρ are constant) (iii) the linear density (when l and t are constant) (b) the pitch of a note (how high or low the note sounds) is determined by the frequency f. (the higher the frequency, the higher the pitch.) use the signs of the derivatives in part (a) to determine what happens to the pitch of a note for the following. (i) when the effective length of a string is decreased by placing a finger on the string so a shorter portion of the string vibrates df dl 0 and l is ⇒ f is ⇒ (ii) when the tension is increased by turning a tuning peg df dt 0 and t is ⇒ f is ⇒ (iii) when the linear density is increased by switching to another string df dρ 0 and ρ is ⇒ f is ⇒

4. now look at the green lines you created by connecting the three boiling point data points and the three melting point data points. for each of these lines, describe any trends you see. 5. locate the elements on your periodic table that you circled in green on your graph. what term or description would you use to identify these elements with respect to the periodic table? 7. using the room temperature line (orange line) and your periodic table, make lists that identify the state of matter (gas, liquid, or solid) in which each element you plotted exists at room temperature. explain your answers.

Which system of units is used by only a small number of countries in the world, including the u.s.