you know spring?

OK. So, from first principles:

• The energy to be stored is what?
• And the size and shape of the spring is what?
• And the force to be applied to achieve the compression needed to store the energy, is what?

Bear in mind that CR4 readers, though highly knowledgeable and experienced, have acheived neither collectively nor individually the ability to mind-read, nor the ability to perform telekinesis.

A 6foot stave of Yew would do that,or a car leaf spring or some bungee cord.

Del

Spring is in the air in southern hemisphere countries.

Assuming that this is a homework question only this.

Take some paper and a pencil (eraser enabled) and jot down what you know about:

Gravity, acceleration deceleration, trajectories, falling bodies, Air Resistance (if not excluded), Springs, tension in springs, deformation, elasticity etc.

You may just as well summarize your handbook for revision purposes.

When you have completed the task try and figure it out on the hand of your list.

If this is not homework give more detail please.

A spring can be found inside your ball point pen. This may or may not be of any use for your application.

Go back to first principles and find out how large a spring you need first.