Linear motion

What is linear motion

• motion in a straight or curved line, with all body parts moving in the same speed in the same direction 

• Its results from a direct force applied to centre of an objects mass.

What is distance

• length of path a body follows when moving to a point

What is displacement

• distance from the start to finish line

• its a vector quantity as it describes size and direction

What is a scalar quantity

• described in terms of size or magnitude

• (mass, distance, speed)

What is a vector quantity

• described in terms of size and direction

• (weight, acceleration, velocity) 

What is speed

• rate of change of position

• its a scalar quantity as dosen’t include direction.

Speed formula

speed= direction/ time taken

what is velocity

• rate of change of position with direction

• its a vector quantity

velocity formula

velocity= displacement/ time taken

what is acceleration

• occurs when velocity increases

• its a vector quantity

acceleration formula

final velocity- initial velocity

             time taken

what is deceleration

• when the rate of change in velocity is negative or decreases over time. 

what does it mean if forces are balanced

• 2 or more forces acting on a body are equal in size but opposite direction 

• weight & direction force are equal

what does it mean if forces are unbalanced

• when force acting in 1 direction is greater than force acting in opposite direction

• resultant force is positive or negative

what are the 4 different forces acting on a performer during linear motion

• weight  friction, reaction, air resistance

how does air resistance affect performer during linear motion

• its the force acting in opposite direction to motion of body travelling through air

• it depends on the velocity of moving object- faster person moved, greater the AR

• depends on shape and surface of moving body- streamline shape or smooth body means less resistance

• DRAG is air resistance in water

how does friction affect performer during linear motion

• it occurs when 2 or more bodies are in contact with one another.

• its affected by surface characteristics, temp, mass (larger mass means greater friction).

• friction allows athletes to push off ground without slipping, maintaining grip on equipment

how does reaction affect performers linear motion

• - occurs when 2 or more bodies are in contact with one another

• whatever force is acting on a performer, there will be a reaction force.

how does weight affect performers linear motion

• its the gravitational pull towards earth to keep performer grounded

• the greater the mass, the greater the weight force pulled down

what is impulse

• change in momentum of an object when acted upon by a force for an interval of time

• impulse= force x time

what does an increase in impulse mean

• increasing impulse will increase the change in momentum, causing change in velocity

how does impulse affect momentum

• using impulse to increase momentum can be done through increasing amount of muscular force applied

• impulse can add speed to body or slow it down on impact