1A Flashcards
(11 cards)
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.
