Newton's Laws of Motion COPY

Question 1

Force

Answer 1

A push or a pull exerted in an object in order to change the motion of the object.

Question 2

Motion

Answer 2

A change in position over time.

Question 3

Net Force

Answer 3

The combination of all the forces acting on an object.

Question 4

Newton’s First Law of Motion

Answer 4

An object’s rest will remain at rest and an object in motion will remain in motion unless acted upon by an outside force.

Question 5

Newton’s Second Law of Motion

Answer 5

Force = mass x acceleration.

Question 6

Newton’s Third Law of Motion

Answer 6

For every action there is a equal but opposite reaction.

Question 7

Inertia

Answer 7

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.

Question 8

Friction

Answer 8

A force that resists motion.

Question 9

Mass

Answer 9

The amount of matter in an object.

Question 10

Gravity

Answer 10

An attraction force that exists between all objects that have mass.

Question 11

Body is at Static Equilibirum as shown below. State the two force equations along the vertical and horizontal axis

Answer 11

T₁Sinϴ₁ + T₂Sinϴ₂ = mg
T₁Cosϴ₁ = T₂Cosϴ₂

Question 12

Body is at Static Equilibirum as shown below. Express the relations between the forces and angles using Lami’s Theorem.

Answer 12

mg/Sinϴ₃ =

T₁/Sin(90+ϴ₂) =

T₂Sin(90+ϴ₁)

Where ϴ₃ = 180-ϴ₂-ϴ₁

Question 13

What is the formula acceleration of the the masses in a simple Atwood Machine?

Answer 13

a = (m₂ - m₁)g
/ (m₁ + m₂)

Question 14

What is the formula Tension of the the masses in a simple Atwood Machine?

Answer 14

T = 2m₁ m₂g
/ (m₁ + m₂)

Question 15

Write the Net Force equations of the following pulley block system?

Answer 15

m₂g - T = m₂a
T = m₁a
N = m₁g

Question 16

What is the relationship between accelerations of the two masses?

Answer 16

a₁ = 2a₂

Question 17

Write the Net Force equations of the following pulley block system -given
a₂ = a?

Answer 17

m₂g - 2T = m₂a
T = m₁a₁=m₁2a
N = m₁g

Question 18

Write the Net Force equations of the following pulley block system -given
a₂ = a?

Answer 18

m₂g - 2T = m₂a
T- m₁gSinϴ= m₁a₁=m₁2a
N = m₁g

Question 19

What is the clamp force on the fixed pulley?

Answer 19

Clamp Force =

Question 20

What does the weighing machine measure?

Answer 20

The weighing machine does not measure the weight but measures the Normal Reaction by acting on the surface.

Question 21

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

Answer 21

1. Stationary case.
   N = mg
   Reading = N/g = m
2. Accelerating upwards with a
   N - mg = ma,
   N = m(g+a)
   Reading = N/g = m(1+a/g)
3. Accelerating downwards with a
   mg-N = ma,
   N = m(g-a)
   Reading = N/g = m(1-a/g)

Question 22

What does the Spring Balance measure?

Answer 22

The spring balance measures the Tension in the string attached to it.

Question 23

What is the formula for the mass Reading (m) by a massless Spring balance ?

Answer 23

T = mg
Reading = T/g = m

Question 24

Write the Net Force equations of the following spring balance?

Answer 24

m₂g - T = m₂a
T - m₁g = m₁a
∴ T = 2m1 m2g
/ (m1 + m2)

Same as the Tension in the Atwood Machine string

Question 25

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

Answer 25

Kl = Constant, ∴K₁l₁ = Kl ∴K₁= Kl /l₁ and K₂= Kl/l₂ | Same as the Tension in the Atwood Machine string

Question 26

A spring with a spring constant of K is split in two and joined in sequence, what is the equivalent spring constant

Answer 26

**1/K_eq = 1/K₁+1/K₂** | Same as the Tension in the Atwood Machine string

Question 27

A spring with a spring constant of K is split in two and joined in parallel, what is the equivalent spring constant

Answer 27

**K_eq = K₁+K₂** | Same as the Tension in the Atwood Machine string

Question 28

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

Answer 28

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.

Question 29

What is Hooke's Law?

Answer 29

F = -kx where, F is Spring Force, K is spring constant x is deformation of spring

Question 30

What is a non-inertial frame of reference?

Answer 30

1. It is accelerated wrt a inertial frame. 2. To make NLM (2nd Law) hold true a **pseudo force** is introduced

Question 31

Express Variable Force as a function of time.

Answer 31

F(t) = m dv/dt ⇒ ∫f(t) dt = ∫m dv (0 to t) (u to v)

Question 32

Express Variable Force as a function of distance.

Answer 32

F(x) = m vdv/dx ⇒ ∫f(x) dx = ∫m vdv (0 to t) (u to v)

Question 33

Express Variable Force as a function of velocity in it's 2 variants.

Answer 33

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)