Forces can cause motion in objects. There are two types of forces - balanced and unbalanced. Balanced forces do not cause motion in stationary objects or a change in motion in moving objects, while unbalanced forces can cause or change motion. Newton's Three Laws of Motion describe the relationship between forces and motion. The first law states that objects at rest stay at rest and moving objects stay in motion unless acted on by an unbalanced force. The second law states that acceleration is produced when an unbalanced force acts on an object and is directly proportional to the net force and inversely proportional to the mass. The third law states that for every action there is an equal and opposite reaction.

1. For ce and Laws
of Mot i on

2. FORCE
A PUSH OR PULL
ON A BODY I S
CALLED FORCE.
FORCES ARE USED
I N OUR EVERYDAY
ACTI ONS LI KE
PUSHI NG,
PULLI NG,
LI FTI NG,
STRECHI NG,
TWI STI NG AND
PRESSI NG.

3. EFFECTS OF FORCE
• A f or ce cannot be seen. A f or ce can
be j udged onl y by t he ef f ect s whi ch
i t can pr oduce i n var i ous bodi es ( or
obj ect s) ar ound us.
1. A f or ce can move a st at i onar y body.
2. A f or ce can st op a movi ng body.
3. A f or ce can change t he speed of a
movi ng body.
4. A f or ce can change t he di r ect i on of a
movi ng body.
5. A f or ce can change t he shape and si ze
of a body.

4. Types Of For ces
THERE ARE TWO KI NDS OF
FORCES:
1. BALANCED FORCE.
2. UNBALANCED FORCE.

5. BALANCED FORCES
1. I f t he r esul t ant of al l t he
f or ces act i ng on a body i s
zer o, t he f or ces ar e cal l ed
bal anced f or ces.
2. I f a number of bal anced
f or ces act on a st at i onar y
body, t he body cont i nuous t o
r emai n i n i t s st at i onar y
posi t i on.
3. I f a number of bal anced
f or ces act on a body i n
uni f or m mot i on, t he body
cont i nuous t o be i n i t s st at e
of uni f or m mot i on.
4. Though bal anced f or ces cannot
pr oduce mot i on i n a
st at i onar y body but can
change t he shape of t he body.

6. UNBALANCED FORCE
I f t he r esul t ant of al l
t he f or ces act i ng on a
body i s not zer o, t he
f or ces ar e cal l ed
unbal anced f or ces.
When an unbal anced
f or ce act s on a body, i t
pr oduces mot i on i n t he
body. Al so, an
unbal anced can st op a
movi ng body.
I f t her e wer e no
unbal anced f or ce of
f r i ct i on or ai r
r esi st ance, a movi ng
body woul d go on f or
ever .

7. NEWTON’ S LAWS OF MOTI ON
NEWTON HAS GI VEN
THREE LAWS OF TO
DEFI NE THE MOTI ON OF
BODI ES. THESE LAWS
ARE KNOWN AS NEWTON’ S
LAWS OF MOTI ON.

8. NEWTON’ S FIRST LAWOF
MOTION
A body at r est wi l l
r emai n i n r est , and a body
i n mot i on wi l l cont i nue i n
mot i on i n a st r ai ght l i ne
wi t h uni f or m speed, unl ess
i t i s compel l ed by an
ext er nal f or ce t o change
i t s st at e of r est or of
uni f or m mot i on.
I NERTI A: I ner t i a i s t hat
pr oper t y of a body due t o
whi ch i t r esi st s a change
i n i t s st at e of r est or of
uni f or m mot i on.

9. MOMENTUM
The moment um of a body i s def i ned as
t he pr oduct of i t s mass and
vel oci t y.
NOTE: t he f or ce r equi r ed t o st op a
movi ng body i s di r ect l y pr opor t i onal
t o i t s mass and vel oci t y.
Thus, moment um= mass x vel oci t y
or , p= m x v
wher e p= moment um
m= mass of t he
body and,
v = speed of t he
body
SI UNI T= t he SI uni t of moment um i s
ki l ogr am met er s per second ( kg. m/ s)

10. NEWTON’ S SECOND LAWOF
MOTION
The r at e of change of moment um
of a body i s di r ect l y
pr opor t i onal t o appl i ed f or ce,
and t akes pl ace i n t he
di r ect i on i n whi ch f or ce act s.
For ce= change i n moment um/ t i me
t aken
f = mv- mu/ t
f = m( v- u) / t . But we know
t hat v- u/ t =a
f = m x a
f or ce = mass x accel er at i on
SI UNI T: i t s SI uni t i s
‘ f or ce’ .

11. NEWTON’ S THIRD
LAWOF MOTION
Whenever one body exer t s a f or ce on
anot her body, t he second body exer t s
equal and opposi t e f or ce t o t he f i r st
body. OR,
To ever y act i on t her e i s equal and
opposi t e r eact i on.
1. EX: t he r ocket wor ks on t he
pr i nci pal of act i on and r eact i on.
2. When a bul l et i s f i r ed f r om t he
gun, a f or ce sendi ng t he bul l et
f or war d i s equal t o t he f or ce sendi ng
t he gun backwar d. But due t o hi gh
mass of t he gun, i t moves onl y a
l i t t l e di st ance backwar d and gi ves
j er k.

12. CONSERVATION OF
MOMENTUM
When t wo or mor e bodi es
act upon one anot her ,
t hei r t ot al moment um
r emai ns const ant
pr ovi ded no ext er nal
f or ces ar e act i ng.
Moment um i s nei t her
cr eat ed nor dest r oyed.
Tot al moment um bef or e
col l i si on = t ot al
moment um af t er
col l i si on

13. THE END
MADE BY:
Ashmeet Goyal