UNIT FIVE: Lab Questions
Trebuchet Throws High-Impact Groceries
1. How does the Shawn reduce the friction of the trebuchet in the
first vídeo ?
He reduces the friction by adding a plastic bearing. With this, the two pieces of wood
aren’t in contact so there’s no friction between them.
2. How did Shawn increase the range on the trebuchet ?
He added a string and a canvas bag. These material lengthens the last wing of the
structure so it works as an extension of the arm.
3. How did Shawn figure out the dimensions of the trebuchet ?
He used the physics rules to figure out the dimensions of the trebuchet. Thanks to
them, Shawn was able to predict were the fruit would arrive and how many time
would pass before it landed. Physic rules are used to make predictions so Shawn used
them to know which measures were needed to attain that a fruit was thrown to a
determinate place.
Building a Temporary Bridge from Cardboard
1. How did Shawn make sure cardboard could hold his weight?
To ensure that the cardboard would be able to hold his weight, Shawn arranged a
prototype structure composed of many triangles. This type of structures are very
strong and distribute the weight equally.
2. What is load analysis?
A load analysis is a test were the engineer measures and tests if the real building
(in this case a bridge) is able to support the weight. In the video, the load analysis
seemed to be passed so Shawn was encouraged to do the final test.
3. What is the maximum reaction force at any joint?
