Newton's Laws of Motion COPY Flashcards
Force
A push or a pull exerted in an object in order to change the motion of the object.
Motion
A change in position over time.
Net Force
The combination of all the forces acting on an object.
Newton’s First Law of Motion
An object’s rest will remain at rest and an object in motion will remain in motion unless acted upon by an outside force.
Newton’s Second Law of Motion
Force = mass x acceleration.
Newton’s Third Law of Motion
For every action there is a equal but opposite reaction.
Inertia
The tendency of an object to resist being moved or, if the object moving, to resist a change in speed or direction until an outside forced acts on the object.
Friction
A force that resists motion.
Mass
The amount of matter in an object.
Gravity
An attraction force that exists between all objects that have mass.
Body is at Static Equilibirum as shown below. State the two force equations along the vertical and horizontal axis
T1Sinϴ1 + T2Sinϴ2 = mg
T1Cosϴ1 = T2Cosϴ2
Body is at Static Equilibirum as shown below. Express the relations between the forces and angles using Lami’s Theorem.
mg/Sinϴ3 =
T1/Sin(90+ϴ2) =
T2Sin(90+ϴ1)
Where ϴ3 = 180-ϴ2-ϴ1
What is the formula acceleration of the the masses in a simple Atwood Machine?
a = (m2 - m1)g
/ (m1 + m2)
What is the formula Tension of the the masses in a simple Atwood Machine?
T = 2m1 m2g
/ (m1 + m2)
Write the Net Force equations of the following pulley block system?
m2g - T = m2a
T = m1a
N = m1g
What is the relationship between accelerations of the two masses?
a1 = 2a2
Write the Net Force equations of the following pulley block system -given
a2 = a?
m2g - 2T = m2a
T = m1a1=m12a
N = m1g
Write the Net Force equations of the following pulley block system -given
a2 = a?
m2g - 2T = m2a
T- m1gSinϴ= m1a1=m12a
N = m1g
What is the clamp force on the fixed pulley?
Clamp Force =
What does the weighing machine measure?
The weighing machine does not measure the weight but measures the Normal Reaction by acting on the surface.
What is the formula for the mass Reading (m) by a weighing machine for ?
1. Stationary case.
2. Accelerating upwards with a
3. Accelerating downwards with a
- Stationary case.
N = mg
Reading = N/g = m - Accelerating upwards with a
N - mg = ma,
N = m(g+a)
Reading = N/g = m(1+a/g) - Accelerating downwards with a
mg-N = ma,
N = m(g-a)
Reading = N/g = m(1-a/g)
What does the Spring Balance measure?
The spring balance measures the Tension in the string attached to it.
What is the formula for the mass Reading (m) by a massless Spring balance ?
T = mg
Reading = T/g = m
Write the Net Force equations of the following spring balance?
m2g - T = m2a
T - m1g = m1a
∴ T = 2m1 m2g
/ (m1 + m2)
Same as the Tension in the Atwood Machine string
A spring of length l with a spring constant of K is split in two of lengths l1 and l2 what are the spring constants of the 2 cut springs
Kl = Constant,
∴K1l1 = Kl
∴K1= Kl /l1
and
K2= Kl/l2
Same as the Tension in the Atwood Machine string
A spring with a spring constant of K is split in two and joined in sequence, what is the equivalent spring constant
1/Keq = 1/K1+1/K2
Same as the Tension in the Atwood Machine string
A spring with a spring constant of K is split in two and joined in parallel, what is the equivalent spring constant
Keq = K1+K2
Same as the Tension in the Atwood Machine string
What are the different forces acting on a stretched or compressed string that is pulled/pushed by hand on one side and attached to a wall on the other side
There are 2 pairs of forces.
1. Force exerted by hand and an opposing spring force.
2. Force exerted by spring on the wall and an opposing Normal reaction on the spring.
What is Hooke’s Law?
F = -kx where,
F is Spring Force,
K is spring constant
x is deformation of spring
What is a non-inertial frame of reference?
- It is accelerated wrt a inertial frame.
- To make NLM (2nd Law) hold true a pseudo force is introduced
Express Variable Force as a function of time.
F(t) = m dv/dt
⇒ ∫f(t) dt = ∫m dv
(0 to t) (u to v)
Express Variable Force as a function of distance.
F(x) = m vdv/dx
⇒ ∫f(x) dx = ∫m vdv
(0 to t) (u to v)
Express Variable Force as a function of velocity in it’s 2 variants.
F(v) = m vdv/dx
⇒ ∫dx = ∫m vdv /F(v)
(0 to x) (u to v)
Or
F(v) = m dv/dt
⇒ ∫dt = ∫m dv /F(v)
(0 to x) (u to v)
