Gravity is a force. It attracts objects with mass towards each other. In space, it might look like there's no gravity, but astronauts are weightless because they're in orbit, so they're ...

So weight is a gravitational force on an object that has mass. The weight of an object may be thought of as acting at a single point called its centre of mass. Depending on the object's shape ...

Mass is the amount of matter in an object ... Show the class a straw and tell them that their mission is to get all four colors stacked in the straw with no foreign objects and no air gaps between the ...

Having collided with the large black hole, the object no longer exists. However, there should be further opportunities to learn more about these mass-gap objects from future collisions ...