Download Sci 1.1 Assessment sched 11

ASSESSMENT SCHEDULE
Science 1.1: Demonstrate understanding of aspects of mechanics
Evidence Statement
One
Expected Coverage
(a)
Achievement
Plotting graph correctly and
drawing of correct graph shapes:
3000
2500
tra
vel
le
d
(m
)
500
0
(b)
1
2
3
4
5
6
e0
(i) Calculation
0
0 of average
0
0 speed:
0
(sec
v = d/t
0
0
0
0
0
0
ond
= 3000/600
s)
= 5 ms-1
(ii) Calculation of distance:
Only applies to section A and C
Area of section A:
0.5 x 400 x 0.8 = 160 m
Area of section C:
0.5 x 500 x 0.8 = 200 m
(c)
Total distance = total area
160 + 200 = 360 m
Explanation of motion:
Section A: Forces are unbalanced,
there is a net force in the forward
direction causing the swimmer to
accelerate.
Section B: Forces are balanced,
there is zero net force, therefore
swimmer moving at constant
speed.
Section C: Forces are unbalanced,
there is a net force in the backward
direction causing the swimmer to
decelerate.
Merit
Excellence
Two of:
Two of:
 in (a), completes
the graph accurately
showing correct
graph shapes for at
least two sections
(with the y axis
labelled correctly).
 in (a), draws
accurate graph with
appropriate shapes
for all three
sections (with the y
axis labelled
correctly).
 in (b), attempts to
calculate average
speed (eg. writes
the formula and
substitutes values
OR finds average
speed but does not
give the unit).
AND
recognises the
distance as the area
under the speedtime graph (eg.
attempt made at
finding an area of
either of the three
sections).
 in (b), calculates
average speed
correctly (with unit)
AND
calculates the area
under at least one
section of the graph
and states the
distance.
 in (b), calculates
average speed
correctly (with unit)
AND
recognises the
speed is only
changing in section
A and C and
therefore only
calculates the area
and distance for the
two sections.
 in (c), shows
understanding that
section B represents
constant speed and
A and C represent
changing speed.
 in (c), states
whether the forces
are balanced or
unbalanced for two
sections of the
graph and links
them to the motion.
 in (c), explains
whether the forces
are balanced or
unbalanced for each
section of the graph
AND
links the direction
of the net force in
section A and C
with the motion.
 In (c) correctly
states whether
forces are
balanced or
unbalanced for
each section.
Both of:
Two
(a)
(b)
Expected Coverage
Calculation of weight:
Fw = mg
= 80 x 10
= 800 N
Explanation of difference:
Mass is the amount of material /
matter in an object.
Weight is the gravitational force
on an object (not the amount of
gravity).
Calculation of work:
Long arms
W=Fxd
= 800 x 0.65
= 520 J
Short arms
W=Fxd
= 800 x 0.60
= 480 J
Achievement
Both of:
 in (a), calculates
the weight correctly
OR
makes an accurate
statement about
mass or weight
 in (a), calculates
the weight correctly
AND
distinguishes
between mass and
weight
 in (b), one
calculation is
undertaken by
selecting and
substituting into the
correct formula and
solving it
 in (b), correctly
calculates work for
both men
AND
calculates power
correctly for one
man OR makes a
statement
comparing work
over the same time
with power.
Calculation of power:
Long arms
P = W/t
= 520 / 2.5
= 208 W
Short arms
P = W/t
= 480 / 2.5
= 192 W
OR statement that both took the
same time to lift weights therefore
the man that did the most work
also exerted the most power.
Comparison with statement:
Man with longer arms did the
most work as he exerted the same
force over a greater distance.
However, man with the longer
arms was also exerting more
power as he did the greater
amount of work in the same time.
Merit
Two of:
 in (b), long
armed man
identified as either
doing the most
work
or
as exerting the most
power
Excellence
Both of:
 in (b), correctly
calculates work for
both men
AND
calculates power
correctly for both
men OR makes a
statement
comparing work
over the same time
with power for both
men.
 in (b), compares
results with
statement and
explains either the
difference in work
Or
difference in power
Three
(a)
(b)
Expected Coverage
Calculation of acceleration:
Fnet = m x a
a = Fnet / m
= 15 / 60
= 0.25 ms-2
Calculation of pressure:
Hayley
P = F/A
Force is
Fw = mg
= 54 x 10 = 540N
Area is that of studs
A = 0.0001 x 12 = 0.0012 m2
P = 540 / 0.0012
= 450 000 Pa
Sarah
P = F/A
Force is
Fw = mg
= 60 x 10 = 600N
Area of both shoes
A = (0.10 x 0.27)x2 = 0.054 m2
P = 600 / 0.054
= 11 111 Pa
Discussion of physics principles:
1. Sarah’s running shoes
have a much larger area
than the studs on
Hayley’s boots.
2. P = F/A so as A
increases the pressure
must get smaller.
3. Even though Sarah is
heavier, her weight is
distributed over a larger
area while Hayley’s is
applied over a small
area.
4. Hayley puts more
pressure on the ground
causing the studs to
‘sink in’ and leave
marks.
Achievement
Merit
Excellence
Two of:
Two of:
 in (a), net force is
calculated
OR
formula correctly
arranged but
incorrect force
value substituted
 in (a), net force
is calculated
AND
correct acceleration
calculated
including unit
 in (b), calculates
the area or weight
force for one person
correctly
 in (b), shows an
understanding of
how the two
formula should be
applied to each
person but fails to
give correct
pressures or units
 in (b), accurately
calculates pressure
for each person
including correct
units
 in (b), states that
Hayley leaves
marks as her boots
exert more pressure
 in (b), shows an
understanding of
the physics
principles involved
by stating that
smaller area of
studs would exert
more pressure than
area of running
shoes
 in (b), explains
that it is the smaller
area of the studs
that results in
greater pressure
AND
the greater pressure
on the ground
leaves marks.
Both of:
Four
(a)
(b)
Expected Coverage
Achievement
Calculation of gravitational pot:
EP = mgh
= 70 x 10 x 2
= 1400 J
Calculation of speed:
1
EK = mv2
2
Assume all gravitational energy
would be converted to kinetic
energy
1
1400 = x 70 v2
2
V2 = 40
V = 6.3 ms-1
Or correct according to (a)
(c)
Description of energy changes:
At point A he has all gravitational
potential energy and no kinetic
energy.
At the bottom of the ramp he has
all kinetic energy and no
gravitational potential energy (the
gravitational potential energy has
been changed to kinetic).
At point B all the kinetic has been
transferred back into gravitational
potential energy.
Merit
Excellence
Two of:
Two of:
 in (a), uses the
correct formula in
an attempt to
calculate
gravitational
potential energy
OR
gives correct value
but no unit
 in (a), calculates
correct
gravitational
potential energy
and gives unit
 in (b), recognises
that gravitational
energy will be
converted to kinetic
energy
OR
selects the correct
formula and
attempts the
calculation by
substituting all
values except v
 in (b), selects the
correct formula and
substitutes
correctly
 in (b), calculates
expected speed
correctly with unit
 in (c), identifies
the type of energy
at each of the three
points (A, bottom
of ramp, and B)
OR
recognises that
energy is being lost
therefore Josh
won’t reach point B
 in (c), accurately
describes the
energy changes
taking place from
point A to point B
OR
recognises that
energy is being lost
as heat therefore
Josh won’t reach
point B
 in (c), accurately
describes the
energy changes
taking place from
point A to point B
AND
recognises that
energy is being lost
as heat due to
friction, therefore
Josh won’t reach
point B
Discussion of energy
conservation:
Between A and B some of the
kinetic energy has been converted
into heat due to friction.
This loss of energy means that
Josh would not be able to reach
all the way to point B.
Both of:
Judgement Statement
Achievement
Achievement with Merit
Achievement with Excellence
Minimum of:
Minimum of:
Minimum of:
3A
3M
3E