Page 128 - Physics

Physics for Secondary Schools

To a great extent, most materials exhibit elastic behaviour. However, there is a limit of
how much the material can deform and be able to regain its original shape. This limit is
known as the elastic limit. Different materials have different elastic limits. If a material
is deformed beyond the elastic limit, it behaves as plastic. Such a deformation is known
as plastic deformation. Therefore, if the elastic limit is not exceeded, there is a defi nite
relationship between tension and extension of elastic materials. This relationship can
be realized by performing Activity 6.1

Acti vity 6.1
Aim: To investigate the relationship between tension applied to an elastic
material and extension.

Materials: Coil spring, pointer, slotted masses, mass holder, metre rule, retort stand
and clamp

Procedure
1. Hang a coil spring on a retort stand as shown in Figure 6.2.

Clamp

Retort stand

Coil spring

Metre rule

Pointer
Mass holder

Figure 6.2
2. Attach the pointer at the free end of the spring and hang the mass holder.
3. Place a metre rule adjacent to the apparatus so that the position of the pointer can
be measured.
4. Measure and record the position of the pointer when there is no mass placed on
the holder as X .
0
5. Place a 50 g mass as shown in Figure 6.3 on the holder, measure and record the
pointer position as X .
1

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Student’s Book Form One

Physics Form 1 Final.indd 122 16/10/2024 20:57