extra work Flashcards
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.
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
During a dive, if a diver goes from a full layout position to a tuck position, what will happen to her angular velocity?
NOT DECREASE
NOT REMAIN THE SAME
increase
Which of the following quantities increases as moment of inertia decreases during the airborne phase of a dive?
Angular velocity
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.
NOT CANNOT BE DETERMINED
NOT THE SAME AS
A net force applied directly through the center of mass of a body:
NOT BOTH A AND B
NOT NEITHER
Consider two objects with the same size, shape, and velocity but different masses flying through the same air at the same time, although the same drag force is applied to both objects the EFFECT of the force on the momentum of each is different.
True
The point of application of a bouyancy force acting on an object is at the ________________ of the object.
Center of Volume
When knee is flexed from anatomical position, what happens to the moment of inertia of the leg about the medio-lateral axis at the hip?
NOT INCREASE
A net force applied directly through the center of mass of a body
changes linear momentum
Consider two objects with the same size, shape, and velocity but different masses flying through the same air at the same time, although the same drag force is applied to both objects the EFFECT of the force on the momentum of each is different.
True
The point of application of a dynamic fluid force force acting on an object is at the ________________ of the object.
NOT CENTER OF PRESSURE
NOT CENTER OF MASS
NOT CENTER OF VOLUME
the buoyancy of a swimmer is influenced by the total body volume of the swimmer.
False only submerged volume
Drag and lift are ALWAYS 90 degrees to one another.
True
The leg extension machine shown in Figure 8.8 in your textbook shows the leg in two positions. The resistance torque (i.e., the torque provided by the machine):
Decreases as the leg reaches full extension