correct order of dominance of empires in West Africa?

How can you prove the mechanical nature of sound by a simple experiment

The diagram shows the set-up for an electric doorbell. Which best explains why the bell would not ring in this set-up? The circuit is open. The electromagnet has an iron core. The circuit is closed. The electromagnet is made of steel.

Consider the two vectors A (with arrow above) = 5i-3j and B (with arrow above) = - i-2j 1. Calculate A (with arrow above) + B (with arrow above) 2. Calculate A (with arrow above) - B (with arrow above) 3.

What is a definition of time distortion?

Use the table below to identify four substances that undergo a physical change if the temperature is reduced from 50oc to - 50oc. what is the physical change that takes place in each case.

A car travels 35.0 mph north for 1.00 hour, then 40.0 mph east for 0.0500 hour, and finally 50.0 mph northeast for 2.00 hours. Calculate the average speed.

A 500 lb steel beam is lifted up by a crane to a height of 100 ft and is held there. A) How much work is being done to hold the beam in place? B) How much work was done to lift the beam?

If Light is shone through the slits of a card onto a sheet of white paper describe what is seen.

When you break a magnet in half, how many poles does each piece have? Explain.

What can you use to unscrew a tiny screw?