17 Questions
What does the coefficient of restitution measure in a collision?
The elasticity of the collision between an object and a given surface
In a perfectly elastic collision, what value does the coefficient of restitution have?
1
How does a high coefficient of restitution (COR) affect a ball's bounce?
The ball bounces higher
What influences the coefficient of restitution (COR)?
Temperature, equipment & surfaces, velocity
If two objects collide and rebound to the same height and velocity, what is the coefficient of restitution for that collision?
1
What is the coefficient of restitution for a perfectly inelastic collision?
=0
Which factor would NOT decrease the resistance to rotational motion of a body according to the text?
Increasing the mass of the body
How does altering the radius affect the moment of inertia of a body?
Decreases moment of inertia if radius is increased
What effect does extending the body during rotation have on the resistance to rotational movement?
Increases it by decreasing moment of inertia
What does angular velocity measure in relation to a body's motion?
Rate of change in angular position
How can a gymnast increase angular velocity during rotation?
Untucking their body to increase AV
What modification could be made to sporting equipment to reduce its moment of inertia?
Decrease the radius
How can adults increase velocity and angular momentum at the point of impact when playing sports like tennis, golf, and cricket?
By using regulation equipment
Which position is hardest to rotate due to its high MOI?
Layout position
In throwing, how does reducing MOI help in achieving a better projectile motion?
By bringing the projectile closer to the shoulder
Which action alters the MOI of a rotating body like a diver or gymnast?
Adjusting body parts around the pivot point
What is the role of mass distribution in relation to MOI when performing a triple somersault or ice skating spin?
Concentrate mass close to center of gravity for faster rotation
Study Notes
Coefficient of Restitution
- Measures the elasticity of the collision between an object and a given surface, represented as a number between 0 and 1
- 1 = perfectly elastic collision, 0 = perfectly inelastic collision, and 0-1 = imperfectly elastic collision
- Influenced by temperature, equipment and surfaces, and velocity
- A high coefficient of restitution (COR) means a high bouncing ball, while a low COR means a low bouncing ball
- A COR of 1 means the object rebounds to the same height/velocity, while a COR of 0 means no rebound
Moment of Inertia (MOI)
- Resistance of a body to rotational movement, calculated as mass x radius2
- Less mass of a body decreases the resistance to rotational motion, while increasing the radius increases the moment of inertia
- Altering the radius leads to a change in MOI, such as a gymnast tucking their head in during a somersault to decrease MOI
Angular Velocity
- The rate of change in angular position of a body, influenced by the moment of inertia
- Increasing the radius of rotation slows rotational movement, increasing MOI, while decreasing the radius increases angular velocity
- Examples include a gymnast tucking their body during rotation to increase angular velocity, or untucking to slow it down
Modifications and Applications
- Modifications made to sporting equipment, such as shortening tennis racquets or golf clubs, reduce MOI and make it easier to use
- The moment of inertia of the human body can be altered in various sports, such as throwing, diving, dancing, and gymnastics
- Techniques used to reduce MOI include bending at the elbow, tucking, and piking, while increasing MOI involves layouts, and spreading arms or legs
Test your knowledge on the characteristics of interacting bodies affecting the coefficient of restitution in sports equipment and surfaces. Explore topics like linear kinetics, energy conservation, and the bounciness of objects in collisions.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
