CONVERSIÓN DE UNIDADES Y SISTEMA INTERNACIONAL DE UNIDADES

Two friends at different locations want to communicate with each other by sending low energy signals. which of the following methods can they use to communicate? a) produce x-rays using colliding electrons and send them to radios, which capture sound b) send messages using infrared radiation, which travel in the form of waves c) send radio waves through intervening media like radio and television d) produce sound waves using microwaves from heated objects

Which actions would increase the rate at salt dissolves in water? stir the water? crush the salt? use less water? heat the water? cool the salt

Which position represents spring in the southern hemisphere? a) b) c) d)