Chapter 16 circular motion Flashcards
What is a radian?
The angle subtended by a circular arc with a length equal to the radius of the circle.
Angle in radians= arc length/radius
How do you convert from degrees into radians?
Degrees * Pi/180
What is the definition of angular velocity?
The rate of change of angle
Omega= theta/time
Are objects on a circular path accelerating?
Yes, they are because as you move in a circular motion the magnitude of your velocity may remain the same but the direction of your velocity is always changing and acceleration is defined as the rate of change of velocity.
What causes an object to travel in a circular path?
A constant net force perpendicular to the velocity of an object. (I.e. acting towards the centre of the circle)
What does any accelerating object require?
A net force.
In which direction does the centripetal force act compared to the velocity?
Perpendicular
Where does the centripetal force come from in the case of a rollercoaster?
Your weight and the normal contact force.
What is the consequence of the centripetal force acting perpendicular to the velocity?
The force (centripetal force) has no component in the direction of motion and so no work is done on the object. Therefore the speed remains constant.
Why does the speed of an object remain constant when travelling on a circular path?
As the centripetal force acts perpendicular to the velocity ( direction of motion ) so there is no component in the direction of motion , so no work is done on the object, so the speed remains constant.
At any point on a circular path where is the linear velocity acting?
In a tangent to the circular path
In what direction does the centripetal acceleration always act?
Towards the centre of the circle.
In what direction does the centripetal force always act?
Towards the centre of the circle.
What provides the centripetal force for a car travelling on a curved path?
Friction
What provides the centripetal force for a pendulum being swung?
Tension
