Circular motion and centripetal acceleration
A constant speed can still have an acceleration.
Key knowledge
For a particle on a circle of fixed radius R, acceleration has inward radial component v²/R and tangential component dv/dt. Uniform circular motion has v=Rω and inward acceleration Rω². “Centripetal force” names the inward net-force component required by the motion; tension, gravity or another interaction supplies it.
Values and equations
a=−(v²/R)e_r+(dv/dt)e_t; v=Rω; a_radial=v²/R=Rω²
- a,a_radial
- Vector acceleration and inward radial magnitude m s⁻²
- v
- Tangential speed m s⁻¹
- R
- Circle radius m
- ω
- Angular speed rad s⁻¹
- e_r,e_t
- Outward radial and forward tangential unit vectors 1
- t
- Time s
Conditions and scope
- R>0; planar motion with a fixed circular centre in an inertial frame.
- For nonuniform speed retain the tangential component; do not add a separate centripetal interaction to an already complete force diagram.
Sources · 1
References
Sources retain their recorded scope. A source link alone does not establish verification of every statement.
Evidence and review
Read §4.4 centripetal derivation, angular frequency and nonuniform-circular-motion decomposition. The force-label clarification follows application of the existing net-force equation, not a separate force law.
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Entry details
Permanent link to this entry ↗- Record identity
- foundation-physics-circular-acceleration
- Revision
- foundations-refresh.1
- Structured reference record
- Foundational reference additions