Stacking Boxes - Center of Mass

On Saturday, my parents and I went to help one of my mom's friends set up a bunch of new computers. There were about 16 Dell monitors and CPUs all boxed up. We decided to unpack them all first and stack the boxes on the side. Since we were busy setting up the computers, I guess no one was really keeping track of the boxes. Everyone would just put their box on the pile when we finished unpacking each component.

As a result, the boxes all fell over. The top three or four boxes were not pushed close enough to the wall and, therefore, the stack's center of mass extended past the support area and the tower collapsed.

Thankfully, all the important computer parts had been taken out so the only consequence was that we had to re-stack all the boxes.

Interestingly, we had the exact same problem later in the day when we were transporting a bunch of small boxes in handcarts. Because there was a hole in the back of the handcart, one of the small boxes fell through as we were moving them. As a result, the entire stack collapsed.

The box's center of mass extended past the small support area of the cart, causing it to fall through the gap. Then, because there was one less box supporting all the other boxes, they all fell off the cart.

Christmas Lights - Circuits

Since we've started learning about circuits, one of the first examples I thought of was with those old Christmas light strands. Although most of the newer ones are wired so that this doesn't happen, my family still uses one of the older kind to run up the middle of our tree. I always remember it as being a pain to set up because having just one of the bulbs broken causes the entire strand to not light up!

Of course, I am very familiar with this aggravating situation as I am always the one drafted to check the lights. I have to check each bulb to see if that is the one that needs to be replaced. Thankfully, we finally bought a newer strand this year. While before, the old strand wouldn't even light up if one bulb was broken this new strand still lights up and somehow bypasses the broken bulb. This makes it much easier to find and replace.

The reason the older strand was so difficult, was because it was wired like a simple circuit in which one broken filament breaks the entire circuit. As a result, the whole strand won't light up because the electrons won't flow through an incomplete circuit with the small voltage difference from the wall outlet.

Anyway, although this entry may be kind of out of season, I thought I'd write about our old Christmas lights since they were the first thing to pop into my head when I was thinking about current electricity.

Unfortunately, our Christmas lights and decorations are away in storage so I had to draw a strand of lights.

Uneventful Weekend - Centripetal Force

Well, I have had a fairly uneventful weekend (too much homework!) so when I remembered I had to do a Physics journal, I was quite at a loss for what to write about. Thankfully, I ran the wash yesterday so I'm going to write about the centripetal force in my washing machine. Unfortunately, I wasn't thinking about taking a picture of the wash so I only have pictures of the empty washing machine.

Anyway, the washing machine utilizes centripetal force during the spin cycle to remove excess water from your clothes so that they aren't dripping wet when you take them out. To do this, the little holes all along the sides of the washer are opened and as the washer continues to spin, centripetal force drives the water out. The water is small enough to fit through the holes and are therefore thrown out tangent to the circle by a lack of a normal force. As a result, all that is left in the washer are your slightly damp clothes which could not possibly escape through the holes.

So, that was my pretty lame journal for this weekend and now I have to go finish all the other homework that has caused my very uneventful weekend. Hopefully next time I will have a more recent physics concept to write about.