A4: rigid body mechanics, Engineering mechanics, Torque, Rotational dynamics

the torque τ of a force about an axis as given by τ = Fr sin θ
• that bodies in rotational equilibrium have a resultant torque of zero
• that an unbalanced torque applied to an extended, rigid body will cause angular acceleration
• that the rotation of a body can be described in terms of angular displacement, angular velocity and
angular acceleration
• that equations of motion for uniform angular acceleration can be used to predict the body’s angular
position θ, angular displacement Δθ, angular speed ω and angular acceleration α,
that the moment of inertia I depends on the distribution of mass of an extended body about an axis of
rotation
• the moment of inertia for a system of point masses as given by I = Σmr2
• Newton’s second law for rotation as given by τ = Iα where τ is the average torque
• that an extended body rotating with an angular speed has an angular momentum L as given by
L = Iω
• that angular momentum remains constant unless the body is acted upon by a resultant torque