Zusammenfassung der Ressource
Circular motion
- The radian
- This is the SI unit for an
angle
- "A radian is the angle subtended by a
circular are with a length equal to the radius
of the circle"
- Degrees*(π/180)= Radians
- Angular velocity
- "The rate of change of angle for an object moving in
a circular path"
- ω=θ/t
- ω=(2π)/T
- ω=2πf
- ω
- rad s^-1
- Centripetal force
- When moving in a circular path, the
direction continuously changes
- Velocity constantly changes
although speed remains the
same
- Hence the object must
be constantly
accelerating
- This acceleration requires a resultant
force (i.e centripetal force), this
always acts towards the centre &
perpendicular to the velocity
- The centripetal force has no component in the
direction of motion
- Gravitational
attraction (Satellite)
- Friction (Car)
- Tensions (String)
- F=(mv^2)/r
- F=m(ω^2)r
- Linear velocity
- The linear velocity is always at a tangent to the circular path
- v=(2πr)/T
- v=ωr
- For a given angular velocity, the linear
velocity at any instance is directly
proportional to the radius
- Centripetal acceleration
- The acceleration
for an object
travelling in a
circular path at
constant speed
- a=-(ω^2)*r
- This acts towards the centre
of a circle