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A tooth with pulpal necrosis typically shows which radiographic feature?

Internal resorption appears radiographically as:

Nelly Korda accelerates the club from the top of the backwing until impact with the ball with an acceleration of 30 rad/s2 for a period of 0.5s. Her radius of rotation is 1.1m. If you want to evaluate her performance by calculating the angular velocity of her club at impact, which equation would you use?

What are the units for angular momentum (H)? 

A 50k diver in a full layout position, with a total body radius of gyration with respect to their transverse principal axis equal to 0.45m, leaves a springboard with an agular velocity of 6rad/s. She tucks her knees into a radius of gyration of 0.25m. To calculate her angular momentum at takeoff, what formula would you use? 

You can increase your stability by: (Choose all that apply)

Which of the following represent appropriate units of measurement for tangential acceleration?

 True or False: Human joints have a fixed axis of rotation.

True or False. As compared to the trunk, hip, and ankle, the knee joint goes through the greatest range of angular motion during a typical gait cycle.

Pickleball is rising in popularity as an ‘easier’ alternative to playing traditional tennis. There are many differences between the two sports. First, the dimensions of a pickleball court are much smaller than a tennis court (Picleball: 20’x 44’long, Tennis: 60′ x 120’long) thus the shear amount of running, cutting, and reaching is reduced in pickleball. As a biomechanist, you should have the tools to describe aspects of the biomechanics of the two sports using terms from angular kinematics and kinetics.  Describe the differences between serves in Pickleball (left image) versus Tennis (right image) where the longitudinal axis of rotation is estimated with a yellow line, and the center of mass (COM) of the player and their racket is estimated with the red circle. You must use the following terms at least once in your response: 1) moment of inertia, 2) center of mass, 3) axis of rotation, 4) mass, and 5)angular velocity and 6)linear velocity. You must comment on a) the differences both due to the motion of different serving types as well as b) the characterstics of each racket.  *the black line on the left indicates a rule in pickleball that the serve has to be executed below that line, which is based on a persons hip height.