An electromagnet is a magnet with a field created by an electric current. To make one is straightforward, according to Jefferson Lab. Take 10 feet of insulated copper wire. Strip off an inch of plastic from each end using wire strippers, to reveal the copper within. Wrap the wire neatly around a 6-inch nail in one direction. Connect the bare ends of the wire to a D-cell battery. You can then use your electromagnet to find out which materials and objects are magnetic.
If you are traveling near the equator, you are ideally placed to do a test about the outflow of water through a central aperture. Some people claim that water drains from a sink in a counterclockwise direction in the northern hemisphere, and vice-versa. Using the water outflow tester, consisting of a jug and funnel, you can find out. Scoop up some water in the jug. Pour it into the funnel and observe which way it rotates as it travels. Do this several times and on both hemispheres for a more rigorous analysis of the phenomenon.
Various outlets sell pinhole camera kits, and one has a clam shell design that prevents any unwanted light entering the camera body. You can easily assemble the camera, which is made of lightweight paperboard and plastic, and you won't need any glue or have to do any cutting. With a pinhole camera, you can, among other things, capture and study the sun's motion over a lengthy period of time. You can even study solar eclipses.
Magnetize a sewing needle by stroking it against a bar magnet in one direction several times. Cut off the end of a cork to make a circular piece about ½-in. thick. Lay this on some water in a saucer. Lay the needle across the diameter of the cork with each end overhanging equally. Very gradually, the needle will turn to point north, if you happen to be in the northern hemisphere, and south if you are in the southern hemisphere.