Angular Motion Flashcards
What is angular motion?
- Refers to rotation and involves movement around a fixed point or axis
When does angular motion occur?
- Occurs when a force is applied outside the centre of mass
What is newtons 1st law?
- Resistance an object has to change in its state of motion
- An object will stay in place till a force is applied to move it
e.g. at the start of a floor routine a gymnast remains still until a force is applied in motion
What is inertia?
- The bodies resistance to change in motion & is related to mass
- If you want to get an object with a large mass moving you have to apply more force in comparason to a tiny object
What is newtons 2nd law?
- The size and direction of the force applied, determines the size and direction of the acceleration given to the object
e.g. to provide acceleration at the start of a race an athlete has to apply a large force internally through the gluteal, gastronemius & quadricpets to drive forward
How do you calculate force?
Force= Mass X Acceleration
What is Newtons 3rd Law?
- For every action there is an equal and opposite force
- Law describes what happens when two bodies (or objects) exert force on one another
- Action & reaction are equal & opposite & always occur in pairs
A&R force e.g swimmer pushes water in backwards direction
Water will then exert force on swimmer
What is the ground reaction force?
- GRF= The equal and opposite force exerted on a performer who applied a muscular force on the ground
- This force is exerted on the ground by the body contact with it
What is the formula for angular velocity?
Angular displacement/ Time taken
What is the formula for angular acceleration?
Change in angular velocity/ Time taken
What is your centre of mass?
- The point of balance
- Centre of mass is always moving depending on your movements
What is the line of gravity?
- The line extending vertically downwards from the centre of mass
Why is stability so important?
- A stable body position will enable an athlete to resist motion
- You cannot perform to your best if you are unbalanced
What is the stability of an athlete affected by?
- The position of the centre of mass
- The position of the athletes line of gravity
- The size of the athletes area of support
- Mass
What factors affect the centre of mass?
- The mass of the body or object
- The size of the base of support- The lower the more stable - but if your mass moves too near base of support you will over balance
- The number of points in contact with the surface
- The closer the line of gravity is to the base of support- the more stable the body