1. identify each of the following as conductors or insulators.

19. cloth

20. dry wood

21. tap water

22. glass

2. light passes from air into water at an angle of 40.0° to the normal. what is the angle of refraction? show all work.

3. a rubber rod can be charged negatively when it is rubbed with wool. what happens to the charge of the wool?

4. what is electrical power in terms of current and potential difference?

5. generate an explanation for the following formula: p = i2r

6. three 15.0-w resistors are connected in parallel across a 30.0-v battery. show all work.

a) find the current through each branch of the circuit.

b) find the equivalent resistance of the circuit.

c) find the current through the battery.

7. what happens to the polarity of an electromagnet when the direction of the current passing through it is reversed?

Um vetor representa um deslocamento cujo módulo é 20 m. se v faz um ângulo de 60 graus com a horizontal, qual é o valor das componentes horizontal e vertical deste vetor?

Use the frequency histogram to complete the following parts. ​(a) identify the class with the​ greatest, and the class with the​ least, relative frequency. ​(b) estimate the greatest and least relative frequencies. ​(c) describe any patterns with the data. female fibula lengths 30.5 31.5 32.5 33.5 34.5 35.5 36.5 37.5 38.5 39.5 0 0.05 0.1 0.15 0.2 0.25 length (in centimeters) relative frequency a histogram titled "female fibula lengths" has a horizontal axis labeled "length in centimeters" from 30.5 to 39.5 in increments of 1 and a vertical axis labeled "relative frequency" from 0 to 0.25 in increments of 0.05. the histogram contains vertical bars of width 1, where one vertical bar is centered over each of the horizontal axis tick marks. the approximate heights of the vertical bars are listed as follows, where the label is listed first and the approximate height is listed second: 30.5, 0.02; 31.5, 0.04; 32.5, 0.05; 33.5, 0.13; 34.5, 0.22; 35.5, 0.25; 36.5, 0.13; 37.5, 0.06; 38.5, 0.09; 39.5, 0.01. ​(a) the class with the greatest relative frequency is nothing to nothing centimeters. ​(type integers or decimals. do not round. use ascending​ order.)

The chart shows daniela’s run through her race. what is her velocity? 1.5 m/s 2 m/s 2.5 m/s 5 m/s