How are electromagnets different from regular magnets?

They can be turned on and off.

Their polarity can be reversed.

Their strength can be changed.

All of the above.

None of the above.

Why does the sun produce energy

A bottle rocket takes off with a = 34.5 m/s2. It fires until it reaches a height of 200 m, then shuts off, and gravity takes over. How much time does it take to reach its maximum height? (Unit = s)

When designing an experiment how do you choose a system to investigate

Why can we feel earthquakes hundreds of miles away?

A transformer is used to convert mechanical energy to electrical energy. answer true false

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?

What shoreline feature would develop if the global sea level were to rise considerably