Science 31st homework

Send me on Thursday all your science homework.

Correction Ex 2
a. heat 2,3,4,6        light 1,5,6
b. artificial 1          natural 6


Today in natural science we are going to answer How does heat travel?

Heat always travels from a hotter object to a colder one. Try to put a hot liquid into a cold container, the heat moves from the liquid to the container. The liquid get colder and the container hotter. Why do you put your sodas in the fridge? to cool them or why when you put some food in the microwave get hotter? or how does the heat from the Sun travel through space? so you are going to learn how all this happens.

Take a look to the video and then read the explanation. It is very easy, do not bother your parents and ask me if you have any question. Use Blogger comments. During this week I will phhone you to check if you have any problem.

CONDUCTION

When two objects are in contact, heat is transferred from one object to the other.This process is called conduction. The  molecules in the hotter object are moving  faster, and have more thermal energy. Heat always travels from a hotter object to a colder one.

When they hit the molecules in the colder object, some of their energy pass to them. As a result, those molecules receive more energy and move faster. The temperature of the colder object increases, and the hotter object gets colder.

CONVECTION

Heat travels through a gas or through liquid by convection. Molecular movement takes place: the

molecules rise up, and the molecules move down. At the bottom, the colder molecules are heated and rise. The transfer of heat into and out of an object by the movement of fluid is called convection.

RADIATION

Particles are needed for the transfer of energy in convection and conduction. Particles aren´t needed for the tranfer of energy in radiation. Head can be transferred through empty spaces by electromacnetic waves. This is called radiation.