First Design
So the first thing we did was look at both of our designs and think to ourselves would they work? After debating on the problems each machine had, we found ways to solve those problems. So both of our designs would probably work in terms of lifting the 600 grams of weight.
However, Ayushi pointed out something very interesting. She looked at my machine and told me that this wasn’t even a compound machine. She explained to me that there was a wheel and axle but a pulley is when one weight pulls another, hens the name pulley. I had comppletly forgotten about that aspect. So we worked it out and found of a way of adding an inclined plane which would increases the mechanical advantage and make it a compound machine.
So far both our machines could work and either way both machines would lift up the 600 grams. So we decided to calculate the mechanical advantage of both machines and compare it. We calculated my design and ended up with approximately 2 mechanical advantage. I think it was a pretty low number because my design was simple and there wasn’t much to it. Next we calculated the mechanical advantage of her design, it was 18. Straight away we knew that it would be much better to use her design then mine. Even though hers was a little more complex it still a much higher mechanical advantage.
After having chosen hers, we divided each part and analyzed it to make sure it would work well. We noticed that we had to decrease the length of the lever or else it would bump into the side wall and not be able to move lower. That was mostly the biggest issue in the design. So we decided to take an A3 paper and make the design with the problems solved.
So the main reason why we decided to use Ayushi’s design was because the mechanical advantage was much higher and it would be a little more complicated using my design considering it wasn’t exactly a compound machine.
This is our first design:
Once looking closely at the design we realised that the design was a bit pointless. The pulley attached to the lever would serve no purpose. Everything would happen with the lever and the pulley would only be there to support it. The pulley would not increase the mechanical or efficiency and not give any help to the job being done. We decided to use the same design but switch it around a bit. Thus giving the pulley a role to play and hoping that it will end up having a larger mechanical advantage and/or efficiency. As you can see below the pulley is only attached to one side of the lever.
The way this machine works is first we add weights into the empty can. The one which is not attached to the lever and just hanging loose on the pulley. The weights will bring down the can and pull the string on the other side of the pulley. The string being pulled is attached to the lever. Therefor pulling the side of the lever up along with the can weighing 600 grams.
This is our final design:
Our compound machine is made of a second-class lever and a block and tackle pulley. The input can is attached to one side of the pulley, and the other side is tied to the lever. The lever has the output can screwed on to it. The two simple machines work together to pull the 600 grams above 5 centimeters above the ground. When the 350 grams is added to the input can, the force pulls the can down and the second pulley of the block and tackle up. Since the lever is attached to that pulley, it also rises up and output can goes up. Our machine is a compound machine because the two simple machines are connected together, and both are equally important for the can to be able rise in the air. Alone, the simple machines are useful, but together the mechanical advantage is much more.
