Exam 2 Review Questions Flashcards
When a pendulum starts from rest and swings 20 degrees in 2 seconds, the average angular velocity is:
10 Degrees
True or False? When swinging your extended arm around in a circle (in a sagittal plane), your elbow has a greater arclength than your wrist?
False
If a pendulum swings forward 30 degrees and then back 10 degrees, the angular distance and displacement are:
distance: 40 degrees, displacement: 20 degrees
True or false? If a body is rotating with a constant angular velocity, the angular acceleration AND the linear, centripetal acceleration of the body are zero.
False,
Even with no angular acceleration, constant angular motion gives rise to a nonzero centripetal acceleration.
The lowercase, Greek letter omega is the symbol used for angular acceleration.
False
Alpha
True or False? If a body segment is rotating with a constant angular velocity, the angular acceleration of the segment AND the linear, tangential acceleration of a point on the distal end of the segment are zero.
True
True or False? One degree is larger than one radian?
False
a radian is larger than a degree
The linear velocity of a point on a body undergoing angular motion is equal to?
(radius)*(angular velocity) where radius is the distance from the axis of rotation to the point.
An angle calculated between the thigh and a horizontal plane is?
An absolute angle
Angular velocity is measured in what units?
Radians/seconds
What is the angle of the knee joint in the anatomical position?
180degrees
With a constant, non-zero angular velocity, the tangential linear velocity of a rotating point about the axis is:
For a given angular velocity of a golf swing, the linear velocity of the head (distal end) of a long club compared to a short club will be:
The motion of the arm during a properly executed throwing motion is such that:
the proximal segments begin to rotate prior to the distal segments.
Consider a person standing in the anatomical position. The moment of inertia of the body rotating about the longitudinal axis is __________ the moment of inertia about the anteroposterior axis.
What is the biomechanical purpose of the patella?
It increases the moment arm of the knee extensors, thus creating more torque for a given muscle force.
Angular momentum can be expressed mathematically as:
moment of inertia * angular velocity
True or False? Angular momentum of a body is not influenced by the application of linear forces to the body
False
As moment of inertia decreases what happens to angular velocity and angular momentum?
he moment of inertia of a moving body is specific to the:
Axis of Rotation
During a dive, if a diver goes from a full layout position to a tuck position, what will happen to her angular velocity?
Increase
Torque is the angular analog of what?
Force
Units for angular momentum and torque?
Angular Momentum: kg m^2/sec
Torque: Newton (N)
Joint torque is influenced by:
- Muscle Force
- Moment Arm