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so

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hello my name is shane kimbrough and i'm

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an astronaut living and working aboard

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the international space station we're

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currently orbiting 250 miles above the

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earth's surface at approximately 17 500

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miles per hour

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you may be wondering how it's possible

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for the space station to be continuously

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orbiting earth well today we're going to

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answer that question and explore

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centripetal force in the microgravity

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environment of the space station

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let's get started

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before we dive into centripetal force

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it's important to look at newton's first

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law of motion which states that an

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object will continue moving with a

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constant velocity along a straight path

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unless acted upon by a net external

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force

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this means that the space station will

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move along a straight path if it weren't

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for one key external force acting on it

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earth's gravitational pull

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another name for this external force is

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centripetal force

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that keeps an object moving along a

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circular path gravity in this case is a

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centripetal force because it is the

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force that is keeping our space station

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moving in its circular path around earth

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all right here's our example we have aki

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here that has an object tied to a string

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it's just a yo-yo but it's an object on

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the end of a string

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he's going to whirl this object around

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attached to the string so that it's

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moving in a circular path

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the string in this demonstration

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provides a force of tension which is the

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centripetal force

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keeping the yoyo revolving around aki's

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hand

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it's important to note that centripetal

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means center seeking therefore a

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centripetal force is a center-seeking

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force

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inward toward the center or axis of

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revolution this is because it's the

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force of tension from the string pulling

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inward that keeps the yoyo revolving

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around the axis of revolution

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now aki's going to set the object moving

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in the circular path free

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and remove that centripetal force by

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releasing the string

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as you saw once the tension from the

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string or triple the force was removed

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the object continues to follow newton's

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first law of motion

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it keeps moving at a constant velocity

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along a straight path relative to the

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space station

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can you think of other examples of

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centripetal forces back on earth

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to learn more about centripetal force

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use the corresponding classroom

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connection to conduct your own

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experiment and discover other ways and

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triple the forces play out in your

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everyday life

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thanks for exploring some physics with

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