1A Flashcards
Explain what is meant by the term ‘angular acceleration’
Rate of change of angular velocity
Explain what is meant by the term ‘central acceleration’.
Rate of change of linear/tangential velocity.
An object is moving in a circular path at a constant speed, explain how it is accelerating.
The object is changing direction and hence its velocity is changing.
An object is moving in a circular path and the central force causing this is removed. State the
direction the object will now move.
The object moves in a straight line tangentially.
State what is meant by a central force
A central force is a force which causes on object to remain in circular motion. It is usually
provided by tension, gravitational force, a magnetic field or friction.
Explain why an object can move faster around a banked circular track than on a flat circular
track.
On a flat circular track only friction provides a central force. On a banked circular track there
is also the reaction force of the track providing a central force.
State what is meant by ‘Torque’.
The turning effect which results from the application of a force at a radius r
A system rotates because a force is applied at a radius ‘r’ from the centre of rotation. An
identical force is applied to the system but at a greater radius. Explain what effect this will
have on the angular acceleration of the system.
The radius has increased meaning the torque (T = Fr) has increased. This means the
angular acceleration increases as T = Iα.
State the law of conservation of angular momentum.
The total angular momentum before a collision is equal to the total angular momentum after
a collision in the absence of external torques.
State what is meant by the term ’moment of inertia’.
A measure of the resistance an object has to changing its angular velocity
Explain what is meant by the term ’moment of inertia’.
A measure of the mass of an object and the distribution of that mass around the centre of
rotation.
