Newton's Law Of Motion Flashcards
Force is ___
1) Push or pull
2) POLAR VECTOR - depends on the point of application
Force has _
1) Magnitude
2) Direction
3) Point of application
Two types of forces
1) Unbalanced force
2) Balanced force
Unbalanced force
…Not an equilibrium
…Shows motion of point of application
…F ( net ) is not equal to 0
Balanced force
…Forces cancel each of the
…In equilibrium
…F (net) = 0
S I unit of force
Newton ( N )
C.G.S unit of force
Dyne
1N = __ Dyne
1 N = 10⁵ Dyne
Newton’s first law of motion is also known as
Law of Inertia
Inertia is directly portional to
MASS
Newton’s first law of motion states that
1 ) If a body is at rest , it remains at rest
2 ) If a body is in motion, then it remains in motion
Three types of inertia are…and explain in one line
1) Inertia of rest : A body at rest remains in rest
2) Inertia of motion : A body in motion remains in motion
3) Inertia of direction : A body cannot change its own direction of motion by itself
Momentum [ P ]
1) Proportional to & formula :
2) Unit :
3) Dimension :
4) Reflect…P = ? :
5) Absorb…P = ? :
1) Proportional to Mass and Velocity__P = mv
2) kg m / sec
3) MLT-¹
4) p = 2mv
5) p= mv
Newton’s second law of motion
External force is directly proportional to the change and momentum with respect to time
F ( ext ) = d(△P) / dt
F (ext)…when velocity is constant
F = v dm / dt
F ( ext ) when Mass is constant
F = m a
a = acceleration
Extra points :
_ acceleration is effect of force
_ a body can have multiple forces but only one acceleration
Average force :
F ( avg ) = P(f) - P(i) / t(f) - t(i)
= △P / △t
Instantaneous force
F (inst) = dp/dt
___( Slope of P v/s t graph ➡️ FORCE )
Or
dp = 《f.dt
___( Area under F v/s t graph ➡️ Change in momentum )
Impulse ( J )
When a large amount of force is applied for a veryy small interval of time is called impulse
J =《f.dt
Rocket propulsion
1) If Rocket is having constant velocity
2) If rocket is having acceleration
1) F (T) = mg
{ F (T) = Thrust force }
v dm/dt = mg
2) F (T) - mg = ma
v dm / dt - mg = ma [1]
Or
a = v dm / m dt - g ( ÷ eq [1] by m )
Gravitational force
_Field force
_Central force
_Line Joining
Mass 1 & Mass 2 shows
_ Attraction force
_ Action reaction force
_ Action = Reaction
g ( gravity ) =
_ 9.8 m/s² ~ 10 m/s²
_ 32 feet / sec ²
_ 980 cm / sec²
Normal force
_ touch force
_ contact force - equilibrium gets distrubed
Normal is always perpendicular to surface of contact .
