Science 8vo_Class 27&28-04-23

Mass and force

Unit 5. Movement and Force

Pages: 120-125

Name the physical characteristics that you can see in a football ball

Look around and you will realize that everything has something that makes it special and unique. However what surrounds us has characteristics that may not always be perceived at first sight.

What characteristics is unique in abody? What characteristics that can’t be seen do bodies have?

But there are characteristics that can’t be observed at first sight. The characteristis that is not so visible in bodies is the amount of matter each one has. The measure unit of mass according to the IS is the kilogram (kg).

Between a wooden cube and a metal cube from the same size, we know that the metal one has more matter, thus it has more mass.

Between two living beings such as dogs, we know that the bigger one has more mass.

The more mass a body has the more difficult it is to stop or move it, but if it has less mass, the application of force required to change its state is less.

The mass of a body is the amount of matter that this one has. In Physics the mass quantifies the inertia in the Universe.

"The mass quantifiers the inertia" means that the more mass a body has the more difficcult it is to stop it, if it is in movement or to change its state if it is at rest.

Weight

All bodies are made by matter (mass) which is attracted by the gravity exerted by Earth. This direct relationship between mass and gravity makes all bodies have a weight.

Weight

Using the formula

If we say that a person has a mass of 80 kg his weight would be of 784 newtons.

Magnitude and direction force

Magnitude

A maganitude is a characteristic of an object that can be measured Length, mass, surface, volume, temperature, are all magnitudes.

Thanks!