forces

Question 1

scalar vs vector

Answer 1

scalar- just magnitude
vector- both magnitude and direction

Question 2

examples of scalar

Answer 2

• time
• mass
• temperature
• distance
• speed
• energy

Question 3

examples of vector

Answer 3

• displacement- distance w direction
• weight
• force
• velocity
• accerleation
• momentum

Question 4

what is a force

Answer 4

push or pull that acts on an object due to the interaction with another objects

Question 5

examples of contact forces

Answer 5

• friction
• air resistance
• tension
• normal contact force

Question 6

examples of non-contact forces

Answer 6

• gravitational force
• electrostatic
• magnetic

Question 7

object’s centre of mass

Answer 7

weight of an object may be considered to act at a single point

Question 8

mass vs weight

Answer 8

• directionly proportional
• mass doesnt change based on where it is
• weight depends on gravitational fild strnegth at the point the objet is
• weight is theforce acting no object due to gravity
• N and measured via newtonmeter

Question 9

what is the resultnat force and how to calculate it

Answer 9

• single force tha can replace no. forces acting on object
• total force on right & then left
• biggest- smallest
• biggest= directiin

Question 10

1J of work

Answer 10

1 Nm

Question 11

work done

Answer 11

energy trasnferred

Question 12

elastic material vs inelastic

Answer 12

elastic- always returns o orignal shape/length if force acting on them is taken awa
inelastc- wont go return

Question 13

for an elastic material to cnage shape/length

Answer 13

2 forces that must be balanced- same magnitude but diff direction

Question 14

if spring is not inelastically deformed, what is the work done equal to?

Answer 14

the elastic potential energy stored

Question 15

what is a moment

Answer 15

turning effect of the force
force x distance
Nm

Question 16

is an object is balanced
moment!!”!”!”£”“£

Answer 16

total clockwise moment = total anticlockwise momet

Question 17

how do levers work

Answer 17

increases the force by increasing the distance or the force applied

Question 18

how do gears work

Answer 18

transmits th turning effect of the force
depnds n radius- and bigger the gears less they move

Question 19

what is a fluid

Answer 19

liquid and gas

Question 19

as the depth increases in water what happens to the pressure

Answer 19

low -> high

Question 20

as density increases what happens to the pressure in a fuid

Answer 20

it increases as larger mass per unit vil- larger weight

Question 22

what is upthrust

Answer 22

resultant force upwards in fluid

Question 23

what causes an object to float

Answer 23

the force of the upthrust is equal to the force of the weight of the object

Question 24

what cause the object to sink

Answer 24

weight more than upthrust

Question 25

what is acceleration

Answer 25

change in velocity in a given time

Question 26

skydiver #mom forces

Answer 26

air resistance- uowards force weight- downwards ^weight- acceleration

Question 27

what is terminal velocity

Answer 27

constant velocity when falling in a fluid

Question 28

density of atmosphere

Answer 28

higher yhe altitude lowever the density

Question 29

why does atmospheric pressure decrease with height?

Answer 29

no. air particles decrease- density less air above surface than ground level

Question 30

ehat is displacement

Answer 30

vector distance from straight line from start to end and direction of line

Question 31

typical speeds when: - walking - running - cycling

Answer 31

- walking- 1.5 m/s - running- 3 m/s - cycling- 6 m/s

Question 32

speed of sound

Answer 32

330 m/s

Question 33

pressure unit

Answer 33

Pascals Pa

Question 34

why does the motion of a circle involve constant soeed but changing velocity?

Answer 34

constant soeed but aleays changing direction

Question 35

any object falling freely under gravity has acceleration of…

Answer 35

9.8 m/s^2

Question 36

what is newtons first law

Answer 36

if resultant force is 0 - object is stationary, it remains stationary - object is mivijg, it continues moving at same speed and direction- same velocity

Question 37

inertia

Answer 37

the tendency of an object to continue in their state of rest or motion

Question 38

newtons second law

Answer 38

acceleration of an objevt is proportional to resuktant force acting in object acceleration is inversely proportional to mass f = ma

Question 39

what is inertia mass and what is it defined as

Answer 39

- measure of how difficult it is to change the velocity of an object - ratio of the force needed to accelerate an object over the acceleration produced larger inertial mass- larger force -> larger acceleration

Question 40

newtons third law

Answer 40

when two objects interact, the forces they exert ok each other are equal and opposites

Question 41

forces acting on a skydiver

Answer 41

- as skydiver jumps out- weight 9doesnt chnage at all) - resuktant forces downwards- accerlate to gound - friction with air molecules- air resitance- eweight still greater - velocity increase- air resitanc increase- air resitance balancing weight = constant velocity=- terminal velocity- very great- can die - parachute- surafec area increase- air resitance increase and greater than weight - decellerate- velocity decrease- air resitanec decreases- balance- terminal velocity- safe to hit ground - -

Question 42

what makes up the stopping distance

Answer 42

thinking & braking

Question 43

what factors affect thinking distanc

Answer 43

- reaction time- ^^ - tiredn - alcohol/drugs - distractions like phone | q

Question 44

avg reaction time

Answer 44

0.2 - 0.9 m/s

Question 45

factors that affect braking distance

Answer 45

- wet/icy roads- less friction - worn tires-^ - worn brakes

Question 46

how do brakes work?

Answer 46

- brakes press against wheel - increases friction - knetic energy to thermal store - decrease in kietci- slows down - increase in therma- heats up

Question 46

high speeds in relatip to braking force why si it so dagerous

Answer 46

- high braking force - overheat - loose control

Question 47

momentum of stationary objects

Answer 47

0 bc no velocity

Question 48

conservation of momentum

Answer 48

in a closed system, the total momentum before an event is equal to total meomntum after an eevent

Question 49

car carshes momentum

Answer 49

rapid changes in momentum

Question 50

how is dangers from momentum reduced

Answer 50

- air bags - crahsmats - seatbelts - bike helmet - cushioned surface on playgrounds | all slow down the change in momentum so not as rapid