linear motion

Question 1

what is linear motion? the movement in a …. or … with all …. the same… at the same ….. in the same..

Answer 1

Is the movement in a straight line or curve with all body parts moving the same distance at the same speed in the same direction

Question 2

do projectiles show linear motion

Answer 2

yes

Question 3

what is parabolic flight

Answer 3

a curve of a projectile

Question 4

what is a vector

Answer 4

vectors are forces that have both a magnitude (size) and direction

Question 5

what are scalar quantities

Answer 5

are when measurements are only described as a magnitude only

Question 6

is mass a scalar or vector

Answer 6

scalar

Question 7

what is an Internal force plus eg

Answer 7

An internal force is applied when our skeletal muscles contract

eg the force produced by the quadriceps when we jump

Question 8

what is an External force plus egs

Answer 8

An external force comes from outside the body

for example friction, air resistance and weight (gravity)

Question 9

identify and explain two external forces acting on the athlete in the photograph (an athlete performing a long jump) the jumping bit (4)

Answer 9

air resistance (1) this will be acting in the opposite direction of travel to the jumper/will depend on the velocity of the jumper/cross sectional area/the streamlining/shape of the jumper (1)

weight/gravity (1) this will be pulling the jumper downwards towards the sand pit/greater the mass of jumper=greater the weight force pulling them down

Question 10

what are the vertical forces

Answer 10

weight, reaction force.

Question 11

identify one vertical force and one horizontal force acting on a performer when running in a 100m sprint

Answer 11

vertical: weight/(ground) reaction force/gravity

horizontal: friction/air resistance

Question 12

what is reaction force

Answer 12

whenever forces act on a performer there will always be a reaction force

Question 13

is friction a vertical or horizontal force

Answer 13

horizontal

Question 14

friction occurs when

Answer 14

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

Question 15

what are the 2 types of friction

Answer 15

sliding and static friction

Question 16

what is static friction

Answer 16

Is the force exerted on one surface by another when there is no motion between the surfaces

Question 17

apply static friction to a netballer

Answer 17

a netballer stationary prior to them using the floor to generate movement

Question 18

what is Sliding friction def and exp explaining which way it acts relative to a runner

Answer 18

Sliding friction acts between two surfaces that are moving relative to one another.

a runner exerts and action force (internal) downwards and backwards in order to move forwards, and so friction acts opposite to this force (forwards), it acts in the same direction as motion (in this case)

Question 19

apply sliding friction to a skier

Answer 19

the slippage is downhill and they are applying force forwards in order to go forwards as there is the additional gravity of going down a hill, and so friction acts opposite to that forward force and so friction acts backwards

Question 20

what are the 3 factors that affect friction

Answer 20

surface characteristics
temperature
mass of object

Question 21

how does surface characteristics affect friction inc eg

Answer 21

running spikes will increase friction of the runner and so will increase accel

ice is smooth and so has/could have “zero friction”

Question 22

how does temperature influence friction inc eg

Answer 22

as temperature increases the amount of friction is reduced eg sweeping the ice in curling

Question 23

how does mass affect friction

Answer 23

as the mass of the object increases, friction increases

Question 24

what is air resistance

Answer 24

A force that acts in the opposite direction to the motion of a body travelling through the air

Question 25

is air res a horizontal or vertical force

Answer 25

horizontal

Question 26

what are the factors affecting air resistance (4things)

Answer 26

velocity of the moving object mass front cross sectional area shape of the surface

Question 27

how does velocity affect air resistance

Answer 27

more velocity=more air resistance

Question 28

how does mass affect air resistance

Answer 28

less mass=more air resistance

Question 29

how does front cross sectional area have an affect on air resistance

Answer 29

the greater the front cross sectional area the more air resistance there is

Question 30

how does the shape of the surface affect the air resistance

Answer 30

a streamlined and smooth shape will create less air resistance

Question 31

what is a net force

Answer 31

The resultant force acting on a body when all forces have been considered.

Question 32

what is a balanced force

Answer 32

Balanced force is when there are two or more forces acting on the body that are equal (inertia) stationary

Question 33

what is an unbalanced force and what is occur as a result

Answer 33

An unbalanced forces when a force acting in One Direction on a body is larger than a force acting in the opposite direction, movement will occur

Question 34

can there be a zero net force/balanced force eg

Answer 34

yes, when standing the weight force and the reaction force are equal in magnitude and in opposite directions and so there is zero net force and there is no change in motion

Question 35

is friction is equal to air resistance the net force is

Answer 35

zero

Question 36

if friction is bigger than air resistance the body will

Answer 36

accelerate

Question 37

is friction is smaller than air resistance the performer will

Answer 37

decelerate

Question 38

is displacement a vector or a scalar

Answer 38

vector

Question 39

is velocity a scalar or vector

Answer 39

vector

Question 40

is acceleration a scalar or vector

Answer 40

vector

Question 41

is weight a a scalar or vector

Answer 41

vector

Question 42

is momentum a scalar or vector

Answer 42

vector

Question 43

units for mass

Answer 43

kg

Question 44

units for displacement

Answer 44

m

Question 45

units for velocity

Answer 45

m/s

Question 46

units for acceleration

Answer 46

m/s^2

Question 47

units for weight

Answer 47

N

Question 48

units for momentum

Answer 48

kg m/s kilogram metres per second

Question 49

definition of mass

Answer 49

Physical quantity expressing the amount of matter or substance in a body from bone muscle fat tissue fluid the quantity of matter a body possesses

Question 50

definition of weight

Answer 50

Downward force on a given mass due to gravity, external force, gravitational force that earth exerts on a body by pulling it down to the centre of the earth

Question 51

the greater the mass of the object the ...... the weight ...... them downwards

Answer 51

greater the weight pulling them downwards

Question 52

is weight a vertical or horizontal force

Answer 52

vertical

Question 53

acceleration definition

Answer 53

Rate of change of velocity

Question 54

displacement definition

Answer 54

Length of a straight-line joining start and finishing points

Question 55

if the length of a race is 1.5km from start to finish in a straight line what is the displacement

Answer 55

1500m

Question 56

if a race is 40km in a loop what is the displacement

Answer 56

0m

Question 57

definition of velocity

Answer 57

The rate of change of displacement (how fast)

Question 58

momentum definition

Answer 58

Product of the mass and velocity of an object

Question 59

formula for weight

Answer 59

weight=mass x acceleration

Question 60

formula for acceleration

Answer 60

accel= change in velocity time

Question 61

formula for velocity

Answer 61

velocity= displacement/ time taken

Question 62

formula momentum

Answer 62

momentum=mass x velocity

Question 63

what is impulse (def) define impulse(2)

Answer 63

amount of time a force is applied to an object/body a measure of force applied over time, impulse = force x time (1) measured in Newton seconds Ns (1)

Question 64

impulse can be manipulated to change which 2 things

Answer 64

momentum or velocity

Question 65

formula for impulse

Answer 65

impulse= force X time (equates to change in momentum unless zero impulse

Question 66

what are the units for impulse

Answer 66

Newton seconds (Ns)

Question 67

is impulse a scalar or vector

Answer 67

vector

Question 68

is positive impulse acceleration or deceleration (and what does that look like on the graph

Answer 68

acceleration it is in the positive force

Question 69

is negative impulse acceleration or deceleration (and what does that look like on the graph

Answer 69

deceleration in the negative half of the graoh

Question 70

what are the units for the axis in an impulse graph

Answer 70

y is force in newtons x is time in seconds or milliseconds

Question 71

on an impulse graph which comes first acceleration or deceleration and why

Answer 71

deceleration as it is the heel strike that causes negative impulse link to newtons 3rd law positive impulse represents front of the footfall

Question 72

if on an impulse graph the + and - are equal what does this mean overall

Answer 72

there is zero impulse as they are equal, they are moving at a constant speed, there is no change in momentum

Question 73

an impulse graph represents one...

Answer 73

footfall

Question 74

the acceleration that a performer achieves when sprinting or high jumping is related to impulse, what do you understand by the term impulse and how does the athletes use impulse during their sprint or take off (3)

Answer 74

impulse is force x time it equates to the change in momentum there is constant mass impulse has direction it represents a single footfall +impulse for accel at take off -impulse when foot lands net impulse positive = accel could draw an annotated graph

Question 75

what is the impulse like at different stages of a 100m sprint

Answer 75

at the start there is positive impulse in the middle there is no impulse at the end there is negative impulse