
1. 3.Rotational dynamics
1.1. Moment of inertia,I = ∑_(i=1)^n▒m_(i r^2 )
1.1.1. The sum of the products of the mass of each particle and the square and its respective distance from the rotation axis.m
1.1.2. scalar quantity
1.1.3. unit- kilogram metre square
1.1.4. Factors that affect I
1.1.4.1. mass of the body
1.1.4.2. shape of the body
1.1.4.3. position of the rotation axis
1.2. Στ=Iα
2. 2.Equilibrium of a uniform rigid body
2.1. Torque,τ ⃗ = r ⃗ × F ⃗
2.1.1. The product of a force and its perpendicular distance from the line of action of the force to the point (rotation axis)m
2.1.2. Rigid body,ΣF ⃗ =F_(nett )= 0
2.1.2.1. A body with definite shape that doesn’t change so that the particles that compose it stay in fixed position relative to one another even though a force is exert on it.
2.1.3. Centre of gravity, CG = the point at which the whole weight of the body may be considered to act
3. 1.Rotational kinematics
3.1. Average angular velocity,ωav= ∆θ/∆t,
3.1.1. The rate of change of angular displacement
3.1.2. Angular displacement,θ= s/r
3.1.2.1. An angle through which a point or line has been rotated in a specified direction in a specified axis.
3.1.2.2. unit in radian (rad)
3.1.3. Relationship between linear velocity, v and angular velocity,ω is v=rω
3.2. Instantaneous angular velocity ω= dθ/dt,
3.2.1. Instantaneous rate of change of angular displacement
3.2.2. vector quantity
3.2.3. radian per second
3.3. Instantaneous angular acceleration α= dω/dt,
3.3.1. The instantaneous rate of change of angular acceleration
3.3.2. vector quantity
3.3.3. radian per second per second
3.4. Average angular acceleration, αav = ∆ω/∆t
3.4.1. The rate of change of the angular velocity
3.4.2. radian per second per second
4. 4.Conservation of angular momentum
4.1. Angular momentum, L=Iω
4.1.1. The product of angular velocity of the body and its moment of inertia about the rotation axis.
4.1.2. vector quantity
4.1.3. unit- kilogram metre square per second
4.2. Relationship between angular momentum, L and linear momentum, p
4.2.1. A vector sums of all the torque acting on a rigid body ism proportional to the rate of change of the angular momentum
4.3. Relationship between angular momentum, L and linear momentum, p
4.3.1. Iω=constant if Στ ⃗ = 0