Forces - Science Unit Test Term 2 Flashcards
learn forces
Why does bending your knees help you balance yourself?
Bending your knees help you balance since when you do the following, your centre of gravity is lower, therefore making it so that you are in closer proximity to the ground and have a decreased chance of tipping over.
What is shear?
Shear is a type of stress that is commonly classified as a internal force that moves parallel on the surface of a material moving into opposite directions.
what is torsion
Torsion is the twisting/ rotational force along a materials length.
what is compression
Compression is an internal force that acts squeezing a material increasing density and decreasing volume. Compression is the opposite of tension.
What is tension
Tension is the opposite of compression. When this occurs, material becomes thinner and stretches in cross section.
What is the difference between torison
and shear
the difference between these 2 internal forces is that torsion is known to be changing the general shape of an object by rotating/ twisting it. Shear are two forces moving parallel in opposite directions, whereas torsion results from twisting forces around the longitudinal axis of a material, causing it to twist along its length.
The general shape of shear can be altered in many ways while torsion has not as many different variants of results.
what makes a hockey stick fling back? and what internal forces are associated with this?
What makes a hockey stick fling backwards is the presence of both internal and external forces causing deformation and energy to the stick. Tension and compression are associated with this since when a hockey stick strikes a puck this results in the bending of the stick, initially causing tension to be stressed upon the top portion, and compression on the bottom portion.
Why do engineers need to think about the format of building something instead of just adding a bunch of support
Focusing on form is more reasonable since Instead of adding excessive support, they aim to distribute loads efficiently throughout the structure. This approach lessens material usage and construction costs while still ensuring the structure’s stability and strength. Also considering that when a structure is placed in a public environment safety is ensured, since even adding lots of support might not be the safest option due to casualties like earthquakes, winds, storms, etc.
What do engineers consider when building a structure?
Engineers also consider factors such as the materials to be used, the type of foundation required, and the connections between structural elements. They aim to optimize the design, balancing factors such as cost, efficiency, and durability.
What are the types of structures?
Shell: Use a thin, carefully shaped, outer layer of material to provide their strength and rigidity.
Frame: These structures are made up of different parts joined together to make a strong frame.
Solid: A solid structure only has one part with no spaces in-between. Solid structures are strong and can support a heavy load.
what is the difference between center of gravity and center of mass?
Centre of mass is the point at which the distribution of mass is equal in all directions and does not depend on gravitational field. Centre of gravity is the point at which the distribution of weight is equal in all directions and it does depend on gravitational field.
What is Lamination?
Lamination consists of composite material consisting of two or more layers bonded together to achieve improved strength, stability and appearance. These layers can be permanently assembled by heat, pressure or adhesive.
What is Corrugation?
Making wavy, rigid patterns on materials to improve effieciency on stability, flexibility and strength.
Examples of Rigid Joints? (list at least 3)
Bolts, Screws, nails,
Examples of Mobile Joints? (List at least 3)
Elbow, door hinge, ballpoint pen (the ball of it is an example of a ball and socket joint).
