Acceleration determined is low for Drop Box

Drop times are too long for drop box or ball fails to drop.

The Drop Box that is used with the Discover Free Fall apparatus uses a solenoid to oppose the magnetic field on permanent magnet. When the circuit closes, the charge stored up within the capacitors within the device flow through the solenoid to oppose the magnetic field generated by the natural magnet. When this field is cancelled out, then the ball can then fall from the device.

if the magnet is a bit too strong, it can retard the movement of the ball away from the attachment point. If the pulse is slightly shorter than needed, the recorded acceleration of the ball will be less as the force from the magnet will slow the fall of the ball and will cause the drop time of the ball to be longer than anticipated.

If the strength of the magnet is too great, then the ball will not be able to separate from the pole piece entirely. Either the ball will release momentarily during the discharge of the capacitors and the ball will be drawn back up to the pole piece (circled in green above), or the ball will remain attached during the entire attempted drop sequence.

For magnets that are a a bit too strong, it can be helpful to place a bit of Scotch tape (cellophane tape) or masking tape over the pole piece of the drop box. Please keep adding layers of tape until the ball just hangs on. This will make sure that the ball will drop from the pole piece and will be far enough away from the pole piece following the discharge of the capacitors that the magnetic force will not significantly affect the acceleration of the ball.