15. Simple Machines (Part 2)

I know we talked about this in class today, but sometimes I still have issues with wheels and axles, like on a bicycle. I don’t understand the directions through which the forces act (like with the back gears).

I think overall I could benefit from a general review of the two problems we worked on yesterday, with the boxes– I think I have the idea, but I’m not sure.

I think I get everything we’ve discussed over the last few weeks, for the most part, but those are the only two things I have trouble with.

14. Simple Machines

Unfortunately my blog isn’t letting me post pictures, but I can describe the things I’ve seen over the weekend. At my church, they’ve been making plans to build a large ramp next to the main entrance stairs. This is an example of a simple machine because it means you’re using less force to move something as you would by simply lifting it. We went to go see a show at a community theater group where they lowered down a disco ball for one of the musical numbers. They achieved this through a pulley system, where one person a distance away could release or pull on the rope in order to change the height of the ball. This made it easier to pull the weight instead of pulling it straight up, as you’re doing the same amount of work with less force.

I’m sure there are plenty of other examples, but I didn’t seem to find many (sorry!)

13. Elasticity

These two different types of balls will have two different masses and will be made up of two different materials. While both most likely have rubber in them, they will have varying amounts of it– a tennis ball deforms more in this case because it will have air inside of it. A bouncy ball will not deform as much because it is a completely solid rubber ball. The more air the ball will have inside of it, the more it will deform because there will be more area for the particles inside the ball to move.

The tennis ball will have more elasticity because it can deform or stretch more. It will probably transfer more energy as well, since it covers more area and is remaining in contact with the ground for longer than the bouncy ball is.

12. Voting

1. I think Jordan’s group had the best idea because of the construction of their catapult. With ones like ours, there’s a lot that can go wrong, because the force exerted on the bird will be different every time. While there’s can be differed a bit by how long you spray the hairspray, there’s less margin for error. They seemed to be very well planned out and the concept, while not the same as the one in the game, will also shoot the birds in a more aerodynamic way.
2. I don’t remember all of the levels exactly, but I really liked a few levels from all three groups. I liked the idea of using cardboard boxes as structures, since they’re easier to move around, but my only worry is that they might break apart if they get wet. Wood is less likely to do that. Using stairs or ramps to move other things, like Dorian’s idea with the watermelon, seems cool as well.
3. I think part of the reason why this was so hard for me was because I still can’t really wrap my head around the concepts. I had trouble with horizontal velocity and vertical velocity, and when we put the two together everything just turned into a big mess. It was still fun to come up with the creative things, though.
4. Yes. I love creating things and doing fun projects– I hope they’ll be more fun in the future because I’ll be less confused.
5. I helped design the models, drew out the plans, and typed up the majority of the presentation. I liked our group, we had good ideas, but like I expressed in my email to you I feel like communication was a big issue. I’ve done my best to get conversation flowing and contribute when I can, but I felt like it wasn’t always clear what we were doing or what direction we were headed.
6. I’ll try to do my best to listen to other’s ideas, and contribute more (like I said, a huge problem for this project was comprehension.)

11. Angry Birds Brainstorming

In my group (myself, Berk, Emily, and Miranda) we worked out what we plan to use for each aspect of the Angry Birds simulator.

The pigs will be balloons filled with water, so they’ll pop when hit like in the game, and eggs will be smaller water balloons. We’ll be using different types of “birds” in varying sizes (a big tennis ball, a softball, etc.) and we’ll cut the tower blocks into thicker and thinner pieces to make the structures different. Points will be awarded based on the pigs you pop and the number of birds you have left.

We haven’t worked it out yet, but we know we’ll need to start the catapult a bit higher off the ground in order to get it to hit the blocks with enough force.

10. Friction

Without friction, anything we applied force to in free space would be sliding around– I wouldn’t be able to push a ball without it rolling super far away. So, in our daily lives, friction is normally pretty cool.

Having friction, however, does have a tendency to make certain things harder. Like in our pHet example, pushing a really heavy box would be much easier on an icy sidewalk than on a wood floor. It’s also really hard when someone’s car breaks down– in order to get them going, you need to give them a push, which would be way easier if there was no friction.

9. Cheerleading

In eighth grade, before I came to Riverdale, I used to do cheerleading. We weren’t the best team, and one of the moves we constantly attempted to perfect was the basket toss–one girl is thrown into the air and two girls on the bottom catch her. I used to be a base, and one of the problems was the fact that our balance was always off. If the flyer was pushing down on our arms with more force than we were at our highest point, then she wouldn’t go anywhere and would fall backwards instead.

In order to get the balance right, we would have to exert equal or more force upwards than she was in the downwards direction, thereby lifting her into the air. This follow Newton’s third law, which states that every action will have an equal and opposite reaction.

8. Tiny Earth Explorer

If he could describe it in one word, it would be magical.

It puzzled him, really, how slow humans were, moving and talking like bumbling giants. And while he definitely hadn’t enjoyed being rudely snatched out of his own home, he appreciated the chance to explore the science of humanism.

Before he knew it, he was exposed to light and color, and he was being tossed into the air. It was as if he were floating, a lone persona in a molasses-like world.

He eyed the meter stick, propped up against a nearby wall, as he rose, wondering how far he’d be able to fly; and then he was spinning, heels over head. He was an astronaut, drifting downwards. If he’d been moving like the humans did, the experience would’ve been terrifying, but he took in the beauty of it all, greens and browns and the wood of a white meter stick and the dark, warm recesses of a human palm.

And that was the story he told his children and his grandchildren, about being a tiny earth explorer in the course of a mere few seconds.

And it was magical.

7. The Scale of the Universe

Upon clicking start, I immediately zoomed all the way out and all the way in to see how far we would be able to go. After doing so, I began from the middle, clicking on different pictures and reading the descriptions.

What was interesting was seeing the two different variables change for every image. Take a human for example. The top number of the description is in meters (so 1.7 in this case) for their height/length and the bottom number is the force of gravity upon the human (1.7 X 10 to the zero power.) Therefore, you can assume that the height/length of something will be directly correlated to the amount of gravitational force is pressing on it.

The little number in the bottom right corner moves from a negative to a positive exponent, depending on how far in you’re zooming. The exponent of the meters times ten to the ___ power will correlate to the scale of the object in relation to the universe.

6. Water in Space

Last year, in Chemistry, we learned a lot about water and surface tension. I believe that–perhaps because they’re in an anti-gravity setting–the water molecules absorbed by the washcloth will have a stronger attraction between them, causing a bubble or film to form. When we wring out a washcloth, gravity draws the water down, creating droplets. Without gravity, there’s nothing pulling down on the water, so it retains its general, uniform state. The video exemplifies this by showing us what happens when he gently lets go of the cloth–the water sticks to his hand because its molecules are still bonded together.