3: Dynamics

Question 1

Newton’s First Law

Answer 1

N1L of motion states that an object at rest will remain at rest, and an object in motion will remain in motion at constant velocity in a straight line in the absence of an external resultant force.

Question 2

Newton’s Second Law

Answer 2

N2L states that the rate of change of momentum of a body is directly proportional to the resultant force and occurs in the direction of the resultant force.

Question 3

N2L equation

Answer 3

F ∝ dp / dt

Question 4

Linear momentum, p formula

Answer 4

p = m v

Question 5

Newton’s Third Law

Answer 5

N3L of motion states that if body A exerts a force on body B, then body B exerts a force of the same type that is equal in magnitude and opposite in direction on body A.

Question 6

Impulse,

Answer 6

Impulse is defined as the product of a force acting on an object and the time in which the force acts.

Question 7

Impulse, ▵p equation

Answer 7

Impulse = F ▵t

Question 8

Principle of Conservation of Linear Momentum (PCLM)

Answer 8

The PCLM states that the total momentum of a system remains constant provided no external resultant force acts on the system.

Question 9

Principle of Conservation of Linear Momentum (PCLM) equation

Answer 9

m₁u₁ + m₂u₂ = m₁v₁ + m₂v₂

Question 10

Conservation of Kinetic Energy (CoKE) equation

Answer 10

u₁ - u₂ = v₂ - v₁

Question 11

Special cases of one-directional elastic collisions:

1. m₁ = m₂
2. m₁ > m₂ (m₂ at rest)

Answer 11

1. Bodies EXCHANGE velocities
2. Velocity of light body REVERSED, massive body stays at REST.
3. Velocity of massive body UNCHANGED, velocity of light body DOUBLES.