Chapter 7 Flashcards
What is the definition of Pi?
The number of times the diameter of a circle wraps around its circumference
What is the definition of 2Pi
The number of times the radius of a circle wraps around its circumference
What is the equation for finding 1 radian?
360 degrees/2Pi = 1 radian (57.3 degrees)
What are the SI units for angular displacement?
Radians
When the arc of motion moves an equal distance to that of the radius of a circle, what is its angular displacement?
57.3 degrees or 1 radian
What is the relationship between the arch of motion and the radius of a circle?
S (arc of motion)/r (radius) = radians
For example:
1/3 =0.333 radians = 19.1 degrees which is 1/3rd of 57.3 degrees.
How can you convert angular velocity in radians to angular velocity in degrees and vice-versa?
Rads - degrees: multiply by 57.3
Degrees - radians: divide by 57.3
What type of acceleration can be used to find angular acceleration?
Tangential acceleration
A rigid body rotating around the x axis will be in which plane?
The YZ plane
What is the difference between point mass idealization and rigid body idealization?
A rigid body has geometry, while a point is treated as an isolated point. Both have mass.
Position vectors can be used to calculate.. ?
Rigid body vectors.
Position vectors are like ‘origin to ankle’ or origin to knee’ whereas rigid body vectors are like ‘ankle to knee - ie leg.
What are the relative and absolute joint angles?
Relative - is relative to other rigid bodies
Absolute - angle of the rigid body relative to the environment
What are the two different types of relative joint angles?
Internal and external
What remains the same and what changes (in terms of joint angles) in jump landings as well as cleans
The leg always goes forward at least 40 degrees. The knee angle is what changes.
Therefore - deep squats and partial squats both involve the same amount of forward leg movement
