How long would it take to charge an iPhone with the kinetic energy of a spinning fidget spinner?
How long would it take to charge an iPhone with the kinetic energy of a spinning fidget spinner?

3 weeks 2 days, 16 hours 12 minutes and 45.3 seconds.

I have to disagree with Smoothy as it may never fully charge up.

14 days, the answer is always 14

According to the Apple's study, it takes about about 10.5 watt-hours of electricity to fully charge the iPhone 6. Using the U.S. average retail price of electricity, which is 12.29 cents per kilowatt-hour, that means fully charging your iPhone 6 once each day for a full year will cost a total of… $0.47. Buying a Fidgit costs more than that, even buying it at Dollar Tree and your hand and wrist won't be disabled.

Rough calculation:

The energy that you impart into a spinner when you flick it is equal to the force from your finger times the length of time you apply that force. Let's make an estimate that the force is 1 newton and is applied for 1/2 second. The amount of energy that you impart is therefor estimated to be 1 N x 1/2 s = 1/2 joule. If we take ma0641's data of 10.5 watt-hours of electricity to fully charge an iPhone, and given that this equivalent to 10.5 watt-Hr x 3600 s/Hr = 37800 joules of energy, this means if you had a way to convert the 1/2 joule of kinetic energy in the fidget spinner into electricity you would have to do this 75,600 times. So - the answer to your question depends om how long it would take you to spin a fidget spinner 75,600 times? If you could do it once per second it would take about 21 hours.

Like I said you will NEVER get it fully charged up! Great math skills though guys.