January 28, 2014:

Rotating "up" or "down" -- is that like clockwise and counter-clockwise?

When you push on a rotating object, when are you doing work?

How can an object spin at constant angular velocity when its parts are accelerating?

Why is easier to keep a bicycle upright when it is moving faster?

January 26, 2014:

When you push someone on a swing, why don't the forces cancel?

Is deceleration something different from acceleration?

January 23, 2014:

How can a basketball weigh 7.5 to 8.5 pounds when blown up but much less when deflated?

Why does a diving bounce up and down after the diver jumps off its surface?

Does a rocket push up on itself?

January 21, 2014:

After one second of falling, a ball’s velocity is about 10 meters per second downward. So why does it travel only about 5 meters downward during that one second?

Why does a sheet of paper on top of a large book fall and land at the same time as the book?

If a wagon is moving on a sidewalk, why doesn't that wagon fall through the sidewalk?

If a ball is thrown horizontally, will it still land at the same moment as a ball thrown straight up?

January 16, 2014:

When you drop a ball, its position changes in a complicated way. How would you calculate that position?

January 14, 2014:

How can an object with a constant velocity have zero net force acting on it? The object is moving, so how could nothing be pushing on it?

Why do objects bounce when they fall on the floor? Does the floor push back up when an object hits it?

When a skater changes direction, so that the skater's velocity changes as a vector quantity, is the skater accelerating?

How do you determine how much force you need to create a particular acceleration?

When you are standing in a constant-moving elevator, what forces act on you besides gravity pulling you down and the floor pushing you up?

When you shake a massive object, why does your body shake, too?