What is the name for all the electromagnetic waves that exist

Ineed asap! list 3 examples in which friction us or makes things easier in our daily life. explain the effect of friction for each. *make sure you explain the effect of friction for each example! *

In a voltaic cell, electrons flow from the (positive/negative) to the (positive/negative) terminal.

A2k pendulum has a speed of 1 m/s at a height of 1/2 meter