Parachute launcher
In order to carry out proper research into parachute design, we need a way of releasing our parachute from a consistent height. The problem that must be overcome is how to make a simple releasing device that can be attached to the end of 3-4 metre pole.

** Remember the idea is to get your parachutes up to the top and release them without going up the pole for every parachute.

A possible design using an electromagnet as a releasing device is given above.
Metal clip attached to each parachute.
Tightly wrapped insulated wire around an iron bolt. This is the electromagnet.
Screw eyes to guide the wire
Each parachute is pulled to the top by pulling on the wires. First connect the wires to the battery to activate the electromagnet. To release the parachute, disconnect the battery.

What is the advantage of using an electromagnet as opposed to permanent magnet?

Are there any other designs that can work for the purpose above?