1. Forces & Motion

Question 1

equation for average speed

Answer 1

average speed = distance moved / time taken

Question 2

equation for acceleration

Answer 2

acceleration = change in velocity ( final speed - initial speed) / time taken

Question 3

what does the gradient give you on a distance time graph

Answer 3

speed= gradient = vertical / horizontal

Question 4

what does gradient give you on a velocity time graph

Answer 4

acceleration= gradient = vertical / horizontal

Question 5

what does the area give you on a velocity time graph

Answer 5

the distance travelled

Question 6

what is the suvat equation

Answer 6

(final speed)2 = (initial speed)2 + (2 x acceleration x distance moved)

v2=u2 + 2as

Question 7

describe the effects of forces between bodies such as changes in speed, shape or direction

Answer 7

???

Question 8

name 7 different types of force ( g r e t d l t )

Answer 8

1. gravity or weight ( always act straight downwards)
2. reaction ( from surface- acts straight upwards)
3. electrostatic ( between 2 charged objects )
4. thrust, push, pull ( speeding smthg up)
5. drag, air resistance, friction ( slow smthg down)
6. lift ( aeroplane wing)
7. tension ( rope or cable )

Question 9

definition of scalar

Answer 9

just value ( magnitude )

Question 10

definition of vector

Answer 10

a value ( magnitude) with direction

Question 11

examples of scalars

Answer 11

mass
temp
time
distance

Question 12

examples of vectors

Answer 12

force
velocity
displacement
acceleration
momentum

Question 13

definition of resultant force

Answer 13

??? the overall force??? not sure

Question 14

how to calculate the resultant force

Answer 14

??? adding or subtracting all the forces that act upon the same line ???

Question 15

what does friction do/ what is friction

Answer 15

a force that opposes motion

Question 16

force equation

Answer 16

force = mass x acceleration

Question 17

weight equation

Answer 17

weight = mass x gravitational field strength

Question 18

what is the stopping distance made up of

Answer 18

sum of thinking distance and braking distance

Question 19

what factors effect the thinking distance

Answer 19

speed

reaction time - tiredness, drugs, alcohol, old age

Question 20

what factors effect braking distance

Answer 20

speed
mass ( with the same brakes )
quality of brakes
grip- road surface, weather conditions, tyres

Question 21

describe the forces acting on a falling object

Answer 21

??? air resistance and weight ???

Question 22

what does terminal velocity of a falling object depend on

Answer 22

shape and area

Question 23

what is the motion of an object falling at terminal velocity

Answer 23

a constant velocity downwards

Question 24

a falling object has a weight of X and an air resistance of Y on it….. what is the net force

Answer 24

X - Y ( subtract the friction because its in the other direction

Question 25

when does terminal velocity occur

Answer 25

??? when friction is equal to objects weight

Question 26

what is the initial linear region of a force- extension graph associated with

Answer 26

Hookes Law

Question 27

what is Hookes Law

Answer 27

extension is proportional to force up until the elastic limit

Question 28

describe elastic behaviour

Answer 28

the ability of a material to recover its original shape after the forces causing deformation have been removed

Question 29

PAPER 2 momentum equation

Answer 29

momentum = mass x velocity

Question 30

PAPER 2 name 3 safety features which momentum is applied to in a car crash- and overall how its works

Answer 30

crumple zones seat belts air bags the longer it takes for change in momentum the smaller the force = less severe injury

Question 31

PAPER 2 describe how crumple zones work

Answer 31

crumple on impact, increasing the time taken for the car to stop

Question 32

PAPER 2 describe how seat belts work

Answer 32

stretch slightly= increasing the time taken for the wearer to stop= reduces forces acting on the chest

Question 33

PAPER 2 describe how air bags work

Answer 33

slow you down more gradually

Question 34

PAPER 2 when is momentum conserved

Answer 34

???? when no external forces act therefore momentum before = momentum after ???

Question 35

PAPER 2 equation for force ( in terms of momentum)

Answer 35

force = change in momentum/ time take for change to happen

Question 36

PAPER 2 what is Newton's 3rd law

Answer 36

Reaction forces forces come in equal and opposite pairs if object A exerts a force on object B then object B exerts the exact opposite force on object A

Question 37

PAPER 2 moment equation

Answer 37

moment = force x perpendicular distance from the pivot

Question 38

PAPER 2 definition of moment

Answer 38

the turning effect of a force

Question 39

PAPER 2 what is the principle of moments

Answer 39

total anticlockwise moments = total clockwise moments

Question 40

PAPER 2 where does the weight of a body act

Answer 40

??? through its centre of gravity ???

Question 41

PAPER 2 what is the centre of gravity of an object

Answer 41

the point through which the weight of a body acts

Question 42

PAPER 2 ??? understand how the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam ???

Answer 42

??? if a light rod is being supported at both ends, the upwards force provided by each support won't always be the same

Question 43

PAPER 2 ??? understand how the upward forces on a light beam, supported at its ends, vary with the position of a heavy object placed on the beam ???

Answer 43

??? if a heavy object is placed on the rod, the sipport closest to the object will provide a larger force

Question 44

definition of mass

Answer 44

how much stuff there is

Question 45

definition of weight

Answer 45

gravity acting on the amount of stuff

Question 46

what is Newton's 1st law

Answer 46

Balanced forces mean no change in velocity (speed) an object will continue at a constant speed ( / velocity ???) in a straight line, unless acted upon by a net force

Question 47

if something is moving at a constant velocity what does that mean about the forces

Answer 47

all the forces acting on it must be balanced

Question 48

when forces are balanced what must acceleration =

Answer 48

0

Question 49

Newton 2nd law

Answer 49

if there is an unbalanced force, then the object will accelerate in that direction ( F = ma )