Ch 03: 2D Motion (Projectile Motion)See all chapters
All Chapters
Ch 01: Units & Vectors
Ch 02: 1D Motion (Kinematics)
Ch 03: 2D Motion (Projectile Motion)
Ch 04: Intro to Forces (Dynamics)
Ch 05: Friction, Inclines, Systems
Ch 06: Centripetal Forces & Gravitation
Ch 07: Work & Energy
Ch 08: Conservation of Energy
Ch 09: Momentum & Impulse
Ch 10: Rotational Kinematics
Ch 11: Rotational Inertia & Energy
Ch 12: Torque & Rotational Dynamics
Ch 13: Rotational Equilibrium
Ch 14: Angular Momentum
Ch 15: Periodic Motion (NEW)
Ch 15: Periodic Motion (Oscillations)
Ch 16: Waves & Sound
Ch 17: Fluid Mechanics
Ch 18: Heat and Temperature
Ch 19: Kinetic Theory of Ideal Gasses
Ch 20: The First Law of Thermodynamics
Ch 21: The Second Law of Thermodynamics
Ch 22: Electric Force & Field; Gauss' Law
Ch 23: Electric Potential
Ch 24: Capacitors & Dielectrics
Ch 25: Resistors & DC Circuits
Ch 26: Magnetic Fields and Forces
Ch 27: Sources of Magnetic Field
Ch 28: Induction and Inductance
Ch 29: Alternating Current
Ch 30: Electromagnetic Waves
Ch 31: Geometric Optics
Ch 32: Wave Optics
Ch 34: Special Relativity
Ch 35: Particle-Wave Duality
Ch 36: Atomic Structure
Ch 37: Nuclear Physics
Ch 38: Quantum Mechanics

Circular Motion

See all sections
Sections
Intro to 2D Motion
Projectile Motion
More Projectile Motion
Initial Velocity in Projectile Motion
Circular Motion

Concept #1: Intro to Circular Motion

Concept #2: More Circular Motion (Practice Intro)

Practice: A Ping-Pong ball goes in a horizontal circle (radius 5 cm) inside a red cup twice per second. Find its:

(a) period;
(b) speed;
(c) centripetal acceleration.

Example #1: More Circular Motion

Practice: A 3kg rock spins horizontally at the end of a 2-m string at 90 rpm. Calculate its:

(a) speed;
(b) acceleration.

Additional Problems
Shown here are the velocity and acceleration vectors for an object in several different types of motion. In which case is the object's velocity changing while its speed is not changing?
You are taking a turn at 30.0 m/s on a ramp of radius 25.0 m. What is your acceleration? A) 20.8 m/s2 B) 0.833 m/s2 C) 1.20 m/s2 D) 36.0 m/s2
In a game of tetherball, the ball is hit such that it spins around the pole at 500 rpm, spinning with a 0.5 m orbit. What is the centripetal acceleration of the tetherball during this motion?
An object is moving with a constant speed of 18 m/s and an acceleration of 4.7 m/s2. Which statement is true? A) This could be a leaf falling from a tree. B) Nonsense. with speed constant, the acceleration must be zero. C) This could be an arrow at the highest point of its trajectory. D) The object moves in a circle.
You spin in a circle with a ball attached to the end of a 1 m string. If the maximum centripetal acceleration the string can withstand is 15 m/s2, what is the maximum number of revolutions you could complete in 1 minute without breaking the string.
An object is moving with a constant speed of 11 m/s and an acceleration of 2.6 m/s2. Which statement is true?A) Impossible. With acceleration, the speed has to change.B) This could be a feather undergoing freefall.C) This is circular motion.D) This could be an arrow at the highest point of its trajectory.
Which of the following is an accurate statement?A) All points on a rotating disk experience the same radial acceleration.B) The vector sum of the tangential acceleration and the centripetal acceleration can be zero for a point on a rotating disk.C) All points on a car tire have zero acceleration if the car is moving with constant linear velocity.D) All points on a rotating disk have the same linear speed.E) All points on a rotating disk have the same angular velocity. 
If the acceleration of an object is always directed perpendicular to its velocity,A) the object is slowing down.B) the object is speeding up.C) this situation would not be physically possible.D) the object is turning.
It is common to see birds of prey rising upward on thermals. The path they take may be spiral-like. You can model the spiral motion as uniform circular motion combined with a constant upward velocity. Assume a bird completes a circle of radius 5.00 m every 5.60 s and rises vertically at a rate of 2.80 m/s. Find the magnitude of the birds’ acceleration.
An object is in a uniform circular motion. Which of the following statements must be true?A) The net force acting on the object is zero.B) The velocity of the object is constant.C) The speed of the object is constant.D) The acceleration of the object is constant.