Lesson 1.3 study questions
Which three factors can be used to describe force?
We describe force in terms of its size/magnitude, direction, and the point at which it acts on a structure
Acceleration and Deformation are the two potential effects when a force acts on an object. Describes them.
Acceleration is the change in velocity of the object which the force is applied. Deformation is a change in shape.
Give two examples of forces the human body commonly encounters.
Bodyweight, friction, and air or water resistance are all forces that commonly act on the human body
Identify the external forces that can act on the body and explain the effects.
Compression - squeezing force, tension - pulling force, shear - force acts perpendicular to the length of the object, stress - resulting force distribution inside a body
Describe how compression and tension differ.
Compression can be thought of as a squeezing force, where is tension is the opposite being a pulling force
What are the three types of directional force distributions that act on the body?
Compression, tension, and shear
How does the amount of stress created vary between a force acting on a small surface and a force acting over a larger surface?
Force acting on a small surface produces greater stress than the same force acting over a larger surface
How is knowledge of kinetic concepts useful?
It is useful for understanding both the movements of the body and the effects of forces that can potentially cause injury
What does it mean when the body's response to a force is plastic?
It means that some amount of deformation is permanent
What is net force?
Net force is the single force resulting from the summation of all forces acting on a structure at a given time
Will a heavier object have greater acceleration then a smaller objects? Why or why not?
No, because the more massive or heavy the object, the smaller the acceleration will be.
The amount of the deformation caused by a given force depends upon what factor?
The amount of the deformation that occurs in response to a given force depends on the stiffness of the object acted on
Describe the factors that determine whether an external force causes bodily injury
The effect of a given force depends not only on his size, direction, and application point but also on the duration of force application
What factors influence whether an injury occurs when an external force is applied to the human body?
The effect of a given force depends not only on its size, direction, and application point but also on the duration of force application
How are pressure and stress quantified?
They are quantified by the size of the force divided by the area over which the force acts
What is the rotary effect of the force called when a force causes a structure to rotate?
Torque
What kind of injury is an acute injury?
When a single force causes an injury, the injury is said to be acute
