Science 3: Intro to Physics

[boy trying to scare another student in the class] about describing the world we already live in so physics is a science that

studies motions and forces and those are all over the place in our day-to-day

lives one of the most important forces gravity it's the force that makes things

fall to the ground if you've ever dropped water balloons out of a window [woman throwing a water balloon out of a window]

you owe gravity a thank you card and if you've never been hit by a falling water

balloon you owe gravity and not cool man card do they make those? [water balloon landing on a boys head]

another important force we see a lot is friction the force that helps moving objects slow

down it's what makes the brakes on our bikes work as friction builds between [woman cycling down the side of a road]

our brakes and the tires our bike gradually comes to a stop which is good

because as much as we like our bikes we don't think we'd want to ride it forever

[man crashing as he rides his bike down the road] so thanks we can see how these two forces interact when we consider

what happens in a sport like ski jumping the skier starts by pushing off from the

top of a very tall hill or mountain gravity pulls them downwards helping [woman skiing down from the top of the mountain]

them go faster and faster building up speed when they hit the jump they fly

up into the air but they come right back down thanks to gravity ski jumping would

probably be a lot less popular if you had to worry about flying in to space [a ski jumper floating around in outer space]

every time you did it finally when the skier wants to come to a stop they turn

their skis into the snow using friction to slow down with all the work they're [skier turning skis into the snow to come to a halt]

doing it kind of seems like gravity and friction deserve a spot on the podium

just saying in fact gravity is so important lots of people who build stuff design [woman on top of a podium waving her skis]

things with gravity in mind that's true whether it's an architect designing a

building using gravity to keep it stable or rocket scientists designing a rocket [a rocket launching from a launch pad]

to escape gravity's powerful pull because no one wants their house

collapsing as soon as it's done or the Rockets hopping up a couple

of feet then landing back on earth even though it might be kind of cool to live [rocket launching but quickly falling back to earth]

in a rocketship and now back to that deep breathing

ahh better