The height of an individual step on a staircase is closest to

What is hidden during a lunar eclipse? isn't the moon hidden?

Spend time observing or thinking about events that involve matter and energy. which events can you explain? which events can’t you explain?

The crank oa rotates in the vertical plane with a constant clockwise angular velocity ω0 of 5.6 rad/s. for the position where oa is horizontal, calculate the force under the light roller b of the 10.6-kg slender bar ab.