Alaser pointer used in a lecture hall emits light at 650 nm what is the frequency

Suppose a wheel with a tire mounted on it is rotating at the constant rate of 2.15 times a second. a tack is stuck in the tire at a distance of 0.373 m from the rotation axis. noting that for every rotation the tack travels one circumference (a) find the tack's tangential speed. (b) what is the tacks radial acceleration?

Which of the following are used in an electrochemical cell? a. electrodes b. electrolyte c. terminals d. all of the above

Identify some abiotic characteristics of the tundra biome.