Pulley Lab

Big Questions

How can force be manipulated using a simple machine?

What pattern do you observe regarding the relationship between force and distance in a simple machine?

Lab 

In this lab we rebuilt the pulley system that we used from the mass vs. force lab. The hardest thing about this lab was probably rebuilding the pulley too because my group and I would always put the string in wrong. No matter how frustrating the string made us, we were still able to accomplish our goal. We found out that it takes 2 Newtons to lift a brass mass .1 meter (10 cm ) without the pulley system and with the pulley system, it only took about 1.3 Newtons to lift a brass mass .2 meters ( 20 cm) which was double what we lifted without the pulley. While we were lifting the brass mass my group also recorded how long the string was. The first time the string was about 20cm  long and the second time it was about 30 cm long. This is when we figured out that force can be manipulated by the distance of the string. We then concluded that if we double the distance then we are also halving the force, which describes the relationship between force and distance.

After we collected all our data we made a bar graph like the one below. We noticed that they all share the same area no matter how tall or wide it may be. Each graph had something different whether it was a high amount of newtons or a long distance but when you find the area you notice that they are all the same. We concluded that no matter what energy or the area would always remain a constant.

Simple Machines

In class we talked about what are simple machines in our daily lives and one that I came up with was a crane. The cables of the crane act as a pulley.  In addition, one that not everybody would think is a lever. On the back of the crane, there is a huge weight that compensate for what is being picked up at the front of the crane. Having a very heavy weight on the back of the crane is essential because it allows a load to be picked up far forward (more distance) at the front of the crane so it can pick up heavier items without tipping over. ( less force)