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"http://yt.cl.nr/T1ux9D7-O38" This video shows 7 different inertia demos. Newton's 1st law of motion (law of inertia) states that objects at rest will remain at rest, and objects moving at constant velocity will remain moving at constant velocity unless acted upon by an outside unbalanced force.

Quiz

"http://yt.cl.nr/iQOHRKKNNLQ" In this segment I ask why astronauts in the space station are weightless. The most common answer is because there is no gravity in space. But of course there is gravity in space, especially where the space station is located (only about 400km from Earth's surface). So astronauts still experience a gravitational pull - it's just that they and the space station are in free fall so they are accelerating together towards the Earth. The space station doesn't crash into the Earth because of its orbital velocity - it's going 28,000 km/h so as it falls, the Earth curves away from it.