A 5.3 kg block initially at rest is pulled to the right along a frictionless, horizontal surface by a constant horizontal force of magnitude 21 N. Find the block's speed after it has moved through a horizontal distance of 6.4 m.

Molten iron fills a mould, which has a volume of 200 cm cubed. calculate the volume when the iron cools and solidifies.

Imagine that you have two balloons (or, better yet, actually inflate two balloons, if possible). create static electricity around one of the balloons by rubbing it against your hair or your sweater and then bring that balloon close to the other balloon, which has not been charged. try this with at least one other object—and for variety in the discussion, avoid using an object already described by your classmates. then, for your initial post to the discussion, answer the following questions: what happened with the two balloons?

What was the first instrument to ever record an earthquake?