2.1 Linear Motion and Force

Question 1

vector quantity

Answer 1

a quantity that has
both magnitude and
direction

Question 2

scalar quantity

Answer 2

a quantity that has
a magnitude but no
direction

Question 3

distance

Answer 3

the total length of
the pathway taken
between the origin
and the destination
point; symbol d

Question 4

displacement
(linear motion)

Answer 4

a vector quantity
representing the
change in position
irrespective of the
path actually taken
between the two
points (symbol: s;
SI unit: metre; unit
symbol: m)

Question 5

resultant

Answer 5

the vector sum of two
or more vectors

Question 6

speed

Answer 6

the rate at which
distance is covered

Question 7

instantaneous
speed

Answer 7

the speed as
measured over a
very small period (an
instant) of time

Question 8

velocity

Answer 8

the rate of change of
displacement of an
object

Question 9

acceleration

Answer 9

the rate of change of
an object’s velocity
(symbol: a; SI unit
symbol: m s–2
)

Question 9

instantaneous
velocity

Answer 9

the rate of change of
displacement over a
short instant of time

Question 10

constant velocity

Answer 10

motion where the
magnitude of the
speed and direction
of the object is
not changing; this
includes an object
at rest

Question 11

uniform
accelerated
motion

Answer 11

motion where the
velocity is changing
in magnitude or
direction in a regular
manner

Question 12

gravity

Answer 12

the force of
attraction between
all masses in the
universe

Question 13

free-fall motion

Answer 13

any motion of a body
where gravity is the
only force acting
upon it

Question 14

contact force

Answer 14

a force where the
object and the action
producing the force
touch each other

Question 15

force

Answer 15

a push or pull
between objects that
may cause an object
or both objects to
change speed and/or
the direction of their
motion or change
their shape (symbol:
F; SI unit: newton; unit
symbol: N)