Biomechanics

Question 0

Impulse

Answer 0

Force multiplied by time it acts for. Change in momentum (J=Ft)

Question 1

Momentum

Answer 1

The property an object has due to its movement (p = mv)

Question 2

Displacement

Answer 2

The difference between the final position and the initial position of a moved object.

Question 3

Force

Answer 3

Any influence that causes an object to undergo a change in speed, direction or shape.

Question 4

Speed

Answer 4

Scalar quantity that refers to how fast an object is moving.

Question 5

Velocity

Answer 5

Vector quantity referring to the rate at which an object changes it’s position

Question 6

Acceleration

Answer 6

The rate of change of velocity as a function of time

Question 7

Centre of mass

Answer 7

The point at which the body mass is equally distributed. The balance point.

Question 8

Distinguish between first, second and third class levers

Answer 8

First class- have a fulcrum in the middle, with the applied force on one side, and the load on the other.

Second class- have the fulcrum at one end, and the applied force on the other, with the load in the middle.

Third class- fulcrum at one end, load at the other end, and applied force in the middle

Question 9

Explain how a change in body position can change the centre of mass

Answer 9

Depending on how the body is positioned, the centre of mass will move. The point at which your body can rotate will be different if you are standing straight VS bent over.

Question 10

Newton’s first law

Answer 10

Every object in a state of uniform motion tends to stay in motion unless an external force is applied to it. (Inertia)

Question 11

Newton’s second law

Answer 11

The relationship between an objects mass ‘m’ and it’s acceleration ‘a’ and the applied force ‘F’ is F=ma. A body or objects change in motion is directly related to the size of force causing the change and will change motion in the direction of applied force.

Question 12

Newton’s third law

Answer 12

For every action there is an equal and opposite reaction

Question 13

Explain how Newtons laws apply to sporting activities

Answer 13

First law- in curling, the faster/heavier you throw the rock, the straighter and farther it will go. Inertia will prevent it from curling and cause it to keep moving in a straight uniform motion.

Question 14

Moment of inertia

Answer 14

The resistance to rotational motion. The bigger the moment of inertia, the larger the moment of force to provide for the angular acceleration. Object moves around an axis.

Question 15

Angular Momentum

Answer 15

Angular velocity x moment of inertia.

Enables explanation of why the rate of spin changes when the moment of inertia changes.

Question 16

Angular velocity

Answer 16

Angular velocity = angle turned (in radians)/time taken to turn
Concept applies to situations where the rate of spin changes with time. (Hammer throw)

Question 17

Explain the factors that affect projectile motion at take off or release

Answer 17

Speed determines how far the object will go.
Angle determines max height of the flight.
Height determines the range of values possible for height/angle.

Question 18

Bernoulli principle

Answer 18

When fluid is moving, (or a body or object is moving through it) the pressure it exerts reduces as it’s velocity increases. The pressure exerted by a fluid is inversely proportional to its velocity. (When pressure is high, velocity is low, and vice versa)

When applied to an object: faster fluid reduces pressure on the object. If there is an uneven pressure, then this will cause the object to move into the area of lower pressure and change direction. (Airplanes move up, because pressure is lower on the top of their wings)