Page 42 - Physics Form 5 KSSM_Neat

(b) Arrangement A: Arrangement B: Arrangement C:
Two springs in Two springs in Three springs T, U and V in
Arrangement of springs series parallel parallel which are in series with
spring W
P Q R S T U V W
KEMENTERIAN PENDIDIKAN MALAYSIA
12 12 12 12 12
(i) Tension / N 12 12 = 6 = 6 = 4 = 4 = 4 12
2 2 3 3 3
2 2 2
(ii) Extension / mm 6 6 3 3 6
2
(iii) Extension of the system 6 + 6 = 12 3 2 + 6 = 8
of springs / mm
(iv) Total length of the 50 + 50 + 12 50 + 3 = 53 50 + 50 + 8 = 108
arrangement of = 112
springs / mm

Formative Practice 1.4

F / N
1. What is the meaning of elasticity?

2. Figure 1.43 shows the graph of force, F against 15
extension, x for a spring. 10
(a) State Hooke’s law.
(b) Does the spring obey Hooke’s law? 5
(c) Calculate the spring constant.
(d) What is the elastic potential energy in the spring 0 x / m
when stretched to an extension of 0.04 m? 0.02 0.04 0.06
Figure 1.43
3. Figure 1.44 shows an arrangement consisting of three 8 N
identical springs P, Q and R. The spring constant is
4 N cm . The arrangement is compressed by an 8 N P
–1
force. Determine:
(a) the force experienced by each spring
(b) the compression of each spring Q R
(c) the compression of the system of springs
Figure 1.44
4. Figure 1.45 shows the graph of F against x for a spring. F / N
The shaded area in the graph has a value of 0.4 J.
(a) What is the force that produces the extension of
5 cm in the spring?
(b) Calculate the spring constant.

0 x / cm
5
Figure 1.45
32