02138020/CAPE/KMS 2021
C A R I B B E A N
E X A M I N A T I O N S
C O U N C I L
CARIBBEAN ADVANCED PROFICIENCY EXAMINATIONS®
PHYSICS
UNIT 1 – Paper 02
KEY AND MARK SCHEME
MAY/JUNE 2021
Page 1 of 4
Question 2
Specific Objectives: Module 2 – 1.1, 1.2, 1.4, 1.9, 1.10, 2.1, 3.1, 3.2,
3.3
(a)
(i)
(ii)
(b)

Amplitude: The maximum displacement of an
object/particle from its equilibrium position
(from a fixed point). (1)
KC
UK
XS
2
Period: The time taken for one complete
oscillation. (1)
The acceleration/restoring force of the object
is always in the opposite direction to the
displacement
OR


(c)
(i)
The acceleration/restoring force of the object is
always directed towards the equilibrium position
(1)
The acceleration/restoring force is proportional
to the displacement (1)
T = 8 S/20 = 0.4 s (1)
m
T = 2π √ k (1)
T2 k
m = 4π2
m =
0.42 × 26.5
4π2
2
4
(1)
m = 0.107 kg (1)
(ii)
ω =
2π
T
(1)
3
2π
ω = 0.4 (1)
ω = 15.7 rad s-1 (1) final answer with unit (1)
OR
�=√
�
(1)
��.�
(1)
�
� = √ �.���
� = ��. � rad s-1 final answer with unit (1)
OR
� = 2�� (1)
Page 2 of 4
�=
(iii)
20
8�
= 2.5 ��
� = 2�(2.5 �−1 )
� = 5� ��� �−� final answer with unit (1)
v0 = ω x0
(1)
= 15.7 × 0.02
(1)
= 0.314 ms-1
(1)
OR
v0 = ω x0
(1)
v0 = �� ��� �−� x 0.02 m (1)
�
v0 =
ms-1
(1)
3
��
Question 2 cont’d
(d)
KC
(i)
UK
XS
5
Correct Amplitude (1)@ 2 cm
Correct Period (1)
Appropriate scale (1)
Amplitude decreasing by 0.2 cm each period (1)
Correct number of oscillations (1)
(ii)
This phenomenon is called damping (1) OR
Damped oscillation
3
Real life applications:
 motor vehicle suspension
 shock absorbers (Shocks)
 door closers,
 swings,
 pendulum, spring mass system
 a bouncing ball.
For any TWO applications, 1 KC EACH
Accept
any
other
reasonable
application
real-life
Page 3 of 4
(e)
(i)
Threshold of hearing is the minimum intensity of
sound that the human ear can detect (1)
OR
Threshold of hearing is the sound level below
which a person's ear is unable to detect any
sound.
OR
The threshold intensity of hearing, I0, is the
smallest intensity of a 1 kHz sound that the
human ear can typically detect.
2
Its value is I0 = 1 × 10-12 Wm-2 (1)
(ii)
dB = 10 lg (I/I0) (1)
(iii)
90 = 10 lg (
109 =
I
I
1 × 10-12
1 × 10-12
1
)
2
(1) for the inverse log
I = 1 × 10-3 Wm-2 (1)
Question 2 cont’d
KC
(iv)
UK
XS
E = Pt and I=P/A
OR
3
E = IAt (1)
A = 0.5 x 10 –4.
OR.
t= 10800s
For conversion of either the area or the time in
SI unit(1)
= 1 × 10-3 × 0.5 × 10-4 × 3 ×3600
= 5.4 × 10-4 J (1)
Total
10
15
5
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