IOP Institute of Physics

# Safety notes

Forces and magnets: Magnet Magic

Possible hazards to be discussed with the teacher BEFORE the visit:

Avoid using small magnets with young children. The children should not drop the bar magnets because the magnets will lose their magnetisation.

Neodymium Magnets (Activities 1, 13, 15, and 16)

• Neodymium Magnets are dangerous because of their strength and the fact that they easily shatter and produce sharp fragments.
• They should all at times be treated with respect and not left with children unsupervised. Nor should primary-age children be allowed to handle them.
• There is a danger of nipped flesh if they are allowed to snap together.
• They should be kept away from electronic apparatus and credit cards, digital cameras, watches, mobile phones, pacemakers etc.
• When the neodymium magnet is dropped down the copper pipe it should land on a soft pad.
• Care should be taken to ensure the magnets do not jump and become attached to a steel shelf bracket or furniture frame and so be lost.

(Activities 2, 10 and 11) The objects and boxes that are handed round should be checked that they do not have sharp edges or places where the children can trap fingers.

(Activity 7) Avoid using iron filings to demonstrate magnetic poles. They stick on magnets and may irritate the skin of younger children. If dressmaking pins are used, take care to collect all of them and not let any fall on the floor. To avoid losing any, they can be placed in a sealed transparent plastic bag which is placed over the magnet on the OHP. Do not allow the children to handle the pins.

(Activity 15) In the wire ‘kick’ demonstration, connect the circuit and then disconnect it after a few seconds to avoid the wire becoming hot. Do not allow the children to help with this experiment.

(Activity 14) The wire and battery in the demonstration electromagnet may become hot due to the large currents flowing. Complete the circuit for only short periods of time. Children like to do this as a class exercise but it is difficult to ensure that some do not leave the circuit connected long enough for it to become hot.

(Activity 16) If the wire in the demonstration motor spins well it will become hot. Demonstrate this where the children will not pick up the wire.

(Activity 18) Any motorised toys demonstrated should be checked to show they are in good condition. Examples of motors that work from the mains should not be used because they would need to have a portable appliance (PAT) test before use.