How Does Inertia Work?

Series Summary

Physical science is an encompassing term for the branches of natural science and science that study non-living systems, in contrast to the biological sciences. The foundations of the physical sciences rests upon key concepts and theories, each of which explains and/or models a particular aspect of the behavior of nature. Physical science can be divided into astronomy, chemistry, earth science and physics. In this free video series, a science teacher provides lessons on the science of electricity and energy sources. Find out how inertia, solenoids and light bulbs work. Learn about wind power, geothermal energy and how nuclear energy is produced. Improve personal knowledge of physical and earth sciences with this information.

Video Transcript

"Hi I'm Steve Jones, and I'm going to tell how inertia works. Or should I say I'm going to tell you how inertia doesn't work, actually. Because inertia is one of those strange things. It's a word which means basically a resistance to doing something. A resistance to changing. People often have inertia, particularly on Monday morning when they have to go to work. There's a certain amount of inertia that they have which stops them somehow getting out of bed and going to work. But really when we talk about inertia in terms of mechanics, we have an object; here's an one hundred kilogram object and I apply a force to it. It has inertia, it doesn't move unless I apply to it a force. And in fact the bigger it is, the bigger the force I have to apply. Therefore, the bigger the inertia is. But also, if I have this object, and it is moving, then there is a resistance to it stop moving. So if I want to stop it I also have to apply a force to stop it moving. So it has inertia in the sense that is has energy within it, which keeps it doing whatever it's doing. If I rotate it, if I spin it, it will continue to spin. And the inertia will be retained, it will continue to spin until I stop it. I will have to apply a force. So inertia basically is a resistance against movement, against changes of movement. So it either resist speeding up, it resist slowing down, it resist changing it's speed of rotation, it resist change. Inertia is about resistance to change."