Calculate the energy released when a 28.9 gram piece of paper is cooled from its melting point of 1083 degrees celsius to 25.0 degrees celsius. the specific heat of copper is .385 j/g celsius.

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

Drag each label to the correct location on the chart. classify each reaction as endothermic or exothermic.

What produces wave a)sound b) heats c)transfer of energy d)vibrations