levers Flashcards
linear motion definition
motion of a straight or curved line where all body parts moving in the same distance, same speed in same direction
newtons first law of motion
law of inertia
if object is at rest, it will remain still
if it is moving in one direction, will continue to do so at the same velocity until a force is exerted upon it
the bigger the mass, the larger the inertia
means more force will be needed to change tis state of motion
if body changes state of motion it will stop, accelerate, decerlate etc
what is inertia
resistance an object has to a change in its state of motion
newtons second law of motion
law of acceleration
magnitude (size) and direction of the force applied to a body determines the magnitude (size) and direction of the acceleration given to the body
the rate of acceleration is directly porportional ti teg force causing the change
force=mass x acceleration
sport example of netons secon law of inertia
to accelerate at the start of their race, sprinter will need to require a large forec internally with their gluetals, quadricaps and hamstrongs as they drive forward
newtons third law of motion
law of reaction
desribes what happens when two bodies exert forces on one another
for every action(force) there is an equal and opposite reaction (force)
most questions involve the GRF (ground reaction force) force exerted on the ground by the body in contact with it
example of newtons third law of motion
sprinter pushes back on blocks as hard as possible (action) and the blocks push forward on the athlete (reaction) adn provides forward acceleration on the athlete
GRF what is it and sport example
GRF-force exterted on the ground by the body in contact with it
an individual standing still exerts a contact force (weight of the individual) and at the same time, equal and opposite GRF is exterted by the ground on the individual
law of inertia in example of football
n penalty, ball remains still (at rest) until it is kicked by the player (an external force is exerted upon it)
law of acceleration in example of football
when the player kicks the ball (force) during the game, the acceleration of the ball is prortional to the size of the force. Harder the player kicks the ball,the further and faster it will go in teh direction the force was applied
law of reaction
when footballer jumps up(action) to win a header, teh force is exerted on teh ground in order to gain height
same time, the ground exertes an upward force (equal and opposite reaction) to the player
scalar quantity
when a measurent is decsribed JUST in terms of its size and magnitude
direction is NOT taken into account
2 examples of scalar quantity measurements
speed and distance
speed definition and equation
speed-change in position
distance covered divided by time taken
distance definition and equation
length of the path a body follows from moving from one position to another
distance=speed xtime
