Akhtar Mahmood (0333-4281759)

M.Sc.(Physics), MCS, MBA-IT, B.Ed.

DEFORMATION MIS, DCE, D AS/400e(IBM), OCP(PITB)

teacher_786@hotmail.com

Deformation: The change in _____________ and ____________ of a solid due to applied force is called
deformation.

Elasticity: (Def.) The property by which a solid returns to its original shape and size when the deforming
force is removed from it is called elasticity.

Example: rubber, nylon, wood, iron (iron is more elastic than rubber) etc.

Extension: (Def.) The ________________in ___________________ due to applied force is called is called
extension.

extension

Compression: (Def.) The _________________in __________________(____________) due to applied force

is called compression.

compressionn

Hooke’s Law:
Statement: _______________________________________________________________________________

________________________________________________________________________________________.

Mathematically form:
F α e
or F = K e,
where K is the constant of proportionality and is called elastic or spring constant. Its value depends upon
the ____________________ of solid. i. e. every solid have different value of K. The value of K for copper
is different than Iron.

Physics by Mr.Akhtar Mahmood 1 SALT Academy 03334281759

 Akhtar Mahmood (0333-4281759)
M.Sc.(Physics), MCS, MBA-IT, B.Ed.
Graphically form: MIS, DCE, D AS/400e(IBM), OCP(PITB)
teacher_786@hotmail.com

e/m
F/N

e/m F/N

The gradient of F/N against e/m graph provides The reciprocal of gradient of e/m against F/N graph
provides value of K. provides value of K.

Point A is the limit o f proportionality (end point of straight). Hooke’s law is valid up to this point.

Point B is the elastic limt i.e. the object will return to its original shape and size when force is removed from it
at this point. Beyond this the object exceed its elastic property and enter into plastic region.

Springs in series:

Physics by Mr.Akhtar Mahmood 2 SALT Academy 03334281759

 Akhtar Mahmood (0333-4281759)
M.Sc.(Physics), MCS, MBA-IT, B.Ed.
MIS, DCE, D AS/400e(IBM), OCP(PITB)
teacher_786@hotmail.com

Q. An extension of 2.0 cm is produced in a spring by a force of 10 N. If three such (identical) springs are
connected in series to a force of 80 N. Calculate the extension produced in the system of springs.

Springs in parallel:

Q. An extension of 2.o cm is produced in a spring by a force of 10 N. If three such (identical) springs are
connected in parallel to a force of 80 N. Calculate the extension produced in the system of springs.

Physics by Mr.Akhtar Mahmood 3 SALT Academy 03334281759

 Akhtar Mahmood (0333-4281759)
M.Sc.(Physics), MCS, MBA-IT, B.Ed.
WORKSHEET OF DEFORMATION MIS, DCE, D AS/400e(IBM), OCP(PITB)
teacher_786@hotmail.com

Q. 1 In an experiment, forces are applied to a spring as shown in Fig. 1.1(a). The results of this experiment are
shown in Fig. 1.1(b).

Fig.1.1(a) Fig.1.1(b)
(a) What is the name given to the point marked Q on Fig. 1.1(b)?

………………….....................................................................................................................................[1]
(b) For the part OP of the graph, the spring obeys Hooke’s Law. State what this means.

.....................................................................................................................................................................

................................................................................................................................................................[1]

(c) The spring is stretched until the force and extension are shown by the point R on the graph. Compare
how the spring stretches, as shown by the part of the graph OQ, with that shown by QR.

.....................................................................................................................................................................

………………………………................................................................................................................[1]

(d) The part OP of the graph shows the spring stretching according to the expression
F = kx.
Use values from the graph to calculate the value of k.

k = ..................................[2]
2. A student wishes to plot an extension/load graph for a spring. He assembles some equipment.
Which of the following is not needed?
A 5 x 1N weights B metre rule C spring and stand D stopwatch

3. The graph shows the variation with load of the extension of a spring. Point P is the limit of proportionality
of the spring. X What will happen if more load is added to the spring
Z A The curve PX on the graph will be produced.
extension B The line PY onn the graph will be produced.
P C The curve PZ on the graph will be produced.
load D The spring will snap.

Physics by Mr.Akhtar Mahmood 4 SALT Academy 03334281759

 Akhtar Mahmood (0333-4281759)
M.Sc.(Physics), MCS, MBA-IT, B.Ed.
Deformation (MCQs Worksheet) MIS, DCE, D AS/400e(IBM), OCP(PITB)
teacher_786@hotmail.com

1. A spring is stretched by hanging a piece of metal 6. Objects with different masses are hung on a 10 cm
from it. spring. The diagram shows how much the
spring stretches.

What is the name given to the force that stretches

the spring?
A friction B mass
C power D weight

2. A student carries out an experiment to plot an

extension / load graph for a spring. The diagrams
show the apparatus at the start of the experiment
and with a load added.

The extension of the spring is directly proportional to

the mass hung on it.
What is the mass of object M?
A 110 g B 150 g C 200 g D 300 g

A spring balance is calibrated to give readings in

7. newtons. The graph shows how the length of the spring
What is the extension caused by the load? varies with the load.
Ax By Cy+x Dy–x

A metal wire, initially 1.000 m long, extends by 4

3. mm when a load of 2 N is added to it.
What will the length of the wire be if a further 3 N
is added, assuming it does not extend beyond
its limit of proportionality?
A 1.060 m B 1.080 m
C 1.010 m D 1.012 m

4. The table shows how the extension of a spring

varies with load.

load / N 0 2 4 6 8 10 12 14 16
extension
0 3 6 9 12 15 20 27 38
/ cm A load causes the spring of the balance to extend by 3
Between which two loads would you find the limit cm. What is the balance reading?
of proportionality? A3N B5N C 10 N D 15 N
A 0 N and 2 N B 8 N and 10 N
C 10 N and 12 N D 14 N and 16 N An extension-load graph is plotted to show the result of
8. increasing the load on a spring.
A spring extends by 4 cm when 10 N is suspended Which point marks the limit of proportionality for this
5. from it. Two of these springs are used as shown to spring?
carry a 30 N load.

What is the extension of each spring?

A 4 cm B 6 cm C 8 cm D 12 cm

Physics by Mr.Akhtar Mahmood 5 SALT Academy 03334281759

Physics by Mr.Akhtar Mahmood 6 SALT Academy 03334281759