This video tutorial explores the properties of contact forces, including compression, tension, shear, and elastic forces. It explains the concepts of systems, external and internal forces, and how they interact. The video uses examples like Lotus on a stool and a party popper to illustrate these forces. It also discusses ideal objects and their simplified properties for easier analysis.

What is a system in physics?

• An object that cannot be influenced by external forces

• A group of objects treated as a single entity

• A single object that moves independently

• A force that acts only within an object

Which of the following is an example of an external force?

• The force between the stool and the ground

• The gravitational pull on Lotus

• The force within a single atom

• The force between Lotus's arm and shoulder

What happens during compression?

• External forces try to stretch an object

• Internal forces cause an object to expand

• Internal forces pull inwards

• External forces squeeze an object

How do internal forces behave during tension?

• They pull inwards

• They push outwards

• They have no effect

• They cause the object to rotate

What is shear?

• Forces that hold an object together

• Forces that compress an object

• Forces that stretch an object

• Forces that make atoms slide past each other

In the context of shear, what does non-collinear mean?

• Forces that do not act in a straight line

• Forces that act in a straight line

• Forces that are opposite in direction

• Forces that are equal in magnitude

What is an elastic force?

• A force that compresses an object

• A force that stretches an object

• A force that returns an object to its original shape

• A force that causes an object to rotate

What is a characteristic of an ideal string?

• It has no mass and does not stretch

• It can stretch and compress

• It has mass and sags under gravity

• It can only maintain a state of compression

Which force prevents solid objects from passing through each other?

• Elastic force

• Shear force

• Normal force

• Tension force

What is the role of internal forces in a system?

• They have no effect on the system

• They act as external forces

• They hold the system together

• They cause the system to accelerate