## Friday, December 2, 2016

### Spin Cycles!

Our washing machines use a lot of energy (or so flyers in freshmen dorms claim), so I decided to investigate that claim, and see just how much energy could be used. In this instance I will only be looking at the spin cycle, and also regardless of water usage and temperature, or vibration, to just see how much energy is required to even spin with the load. To do this, I will angular mechanics to figure out how much energy (Joules) was used in order to wash a full load of clothes.

CR-Home-AH-Compact-Washers-03-16.jpg (http://consummerreports.org)

In order to find the energy done, I will find the kinetic energy of the drum spinning.
While washing machines take 36 mins to wash a full load, but only 8 minutes for the actual spin cycle. As the average speed of a spin cycle is 1000 RPM, we must convert it into angular velocity in order to calculate the angular kinetic energy.
Next, we must take the mass of the laundry/clothing load on the machine, 2.7kg for a full one, and add the weight of the steel washing drum, which is estimated to be about 16kg; making a total of 18.7kg. Along with that, the radius for the drum is estimated to be around .5 m. After which, we can plug these variables into our equation, and finally, multiply the result by 8 as there are 8 minutes.

Therefore, for just the spin of a machine, you use 205,000 J for each load of laundry you use. So yeah, I do believe the flyers when they say they "take a lot of power." Do your laundry wisely!