Forces

Question 1

6 scalar quantities

Answer 1

mass
temp
speed
energy
distance
time

Question 2

what makes a quantity scalar

Answer 2

have magnitude only
no direction

Question 3

6 vector quantities

Answer 3

velocity
displacement
weight
acceleration
momentum
force

Question 4

what makes a quantity vector

Answer 4

has magnitude +direction

Question 5

what are vectors reperesented with

Answer 5

an arrow

Question 6

length of arrow represents…

Answer 6

magnitude of vector

Question 7

define force

Answer 7

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

Question 8

are forces scalar or vector

Answer 8

vector

Question 9

unit for force

Answer 9

newton

Question 10

2 catogories for forces

Answer 10

contact
non contact

Question 11

what is meant by contact force

Answer 11

objects physically touching

Question 12

what is meant by non contact force

Answer 12

objects physically separated

Question 13

what is meant by non contact force

Answer 13

objects physically separated

Question 14

4 eg contact force

Answer 14

tension in rope
friction
air resistance
normal contact force

Question 15

what does force of tension do in tug of war

Answer 15

force of tension pulls on the person

Question 16

what does force of friction do when aeroplane lands on sea

Answer 16

force of friction causes plane to slow down and stop

Question 17

what happens when sky diver falls through air

Answer 17

air particles collide with parachute
force of air resistance acts upwards

Question 18

when does a normal contact force happen

Answer 18

when objects are in direct contact

Question 19

normal contact force:
what type of force does lamp exert on table

Answer 19

lamp exerts downward force on table which is its weight

Question 20

normal contact force:
what does table do

Answer 20

exert upwards force on lamp

Question 21

3 eg non contact force

Answer 21

gravitational force
electrostatic
magnetic force

Question 22

what does gravitational force do

Answer 22

attracts all objects to other objects

Question 23

the electrostatic force is the force between

Answer 23

2 charged objects

Question 24

what is experienced by objects with opposite forces

Answer 24

electrostatic force of attraction

Question 25

what is experienced by objects with the same type of charge

Answer 25

electrostatic force of repulsion

Question 26

what is the magnetic force

Answer 26

force experienced by certain objects in a magnetic field

Question 27

gravity is a force of……

Answer 27

attraction between all objects

Question 28

is gravity vector or scalar

Answer 28

vector

Question 29

what does mass of an elephant tell you

Answer 29

how much matter in the elephant

Question 30

unit of mass

Answer 30

kj

Question 31

is mass scalar or vector

Answer 31

scalar( no direction)

Question 32

does mass change depending on where object is ?

Answer 32

no

Question 33

does mass change depending on where object is ?

Answer 33

no

Question 34

the weight of an elephant is the

Answer 34

force acting on the elephant due to gravity

Question 35

unit for weight

Answer 35

newton

Question 36

does weight change depending on where object is ?

Answer 36

yas

Question 37

symbol for gravitational field strength

Answer 37

g

Question 38

gravitational field strength is a measure of

Answer 38

the force of gravity in a particular location

Question 39

what amount of force do objects on surface of earth experience

Answer 39

force of 9.8N for every kg of their mass

Question 40

unit for gravitational field strength

Answer 40

N/Kg

Question 41

weight and mass of object are directly or indirectly proportional?

Answer 41

directly

Question 42

what does directly proportional mean

Answer 42

if we double mass, weight also doubles

Question 43

how to work out objects weight

Answer 43

use calibrated spring balance ( newtonmeter)

Question 44

does gravitational field strength depend on location

Answer 44

yes

Question 45

define meaning of objects centre of mass

Answer 45

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

Question 46

define force

Answer 46

push/ pull that acts on object
due to interaction with another object

Question 47

are forces vector/ scalar

Answer 47

vector

Question 48

what is resultant force

Answer 48

single force that has same effect as all the original forces acting together

Question 49

how to work out resultant force

Answer 49

larger force minus smaller force

Question 50

give example when resultant force is 0

Answer 50

skydivers weight is 800N (downward force)
air resistance is 800N (upward force)

Question 51

how are free body diagrams drawn

Answer 51

object shown as a point
forces drawn as arrows starting at the point

Question 52

what does length of arrow in free body diagram show

Answer 52

strength of force

Question 53

what does altitude mean

Answer 53

height above ground

Question 54

describe free body diagram for plan flying at constant altitude and constant velocity

Answer 54

dot in centre of 4 arrows
arrows at right angles to each other
lift acts upward
weight acts downward
air resistance to left
thrust to right

lift and weight arrows same length
air resistance and thrust arrows same length

   ^
    l <--- 0 --->
    l

Question 55

How would you solve this question?
Two forces are acting on an object. One force has magnitude of 10 N. Another force has magnitude of 8N. Angle between the two forces is 30 *. Calculate resultant force

Answer 55

Make vector/ free body diagram for the two forces involved
say 1cm = 1N

put point on page.
use ruler, draw 10cm long arrow (for the 10N force)
use protractor to measure angle of 30*
Use ruler to draw 8cm long arrow ( for 8N force)

Now make a paralellogram

copy the 8cm line, at the head of the 10cm arrow
copy the 10cm line , at the head of the 8cm arrow
make sure exterior angles are 30*

Draw lines from tail of vectors to opposite side
(horizontal line splitting parallelogram in two)