Introduction to Middle school physics | Khan Academy

Hi everyone! Sal Khan here and welcome to Middle School Physics. I have Iman Howard who manages all of our STEM content.

Iman, why should folks be excited about Middle School Physics?

So, Middle School Physics is like the only science out there that explains how things happen. Basically, everything's made of matter—me, you, um, the chair that I'm sitting on. This course is going to explore how we exist in the natural world. For example, we talk a little bit about movement and forces, and we learn that everything—everything that we have a collision with—has this equal but opposite force that's applied when the collision happens.

That's why when you give those high fives and then your hand starts stinging, it's because the same force you gave your buddy is the same force they gave you back. Then we also talk about force in a way where it doesn't touch you. I'm thinking like Star Wars—there's like this force energy, like gravitational, there's magnetic energy, there's electric energy.

And then finally we get into waves, and we talk a little bit about how waves exist—whether it's sound waves or even the waves in the ocean.

What do you think's exciting?

Oh, well, that's a dangerous question to ask me! I wanted to be a physicist, and I still aspire to be it because, you know, we kind of wake up in this cosmos and we're just trying to understand where we fit in. Physics asks the most fundamental questions about how the universe works.

When I first learned about Newton's laws and fields and all the things that you just touched on, it started to give me goosebumps because I'm like, wow, we can finally understand how the universe fits together and then use that to make predictions and think about things that we don't understand.

And there is so much that we don't understand! So I think this is the beginning of a very, very exciting journey in physics.

I agree!