Presentation on theme: "An object moving in uniform circular motion is moving in a circle with a constant speed. uniform: not changing in form or character; remaining the same."— Presentation transcript:
An object moving in uniform circular motion is moving in a circle with a constant speed. uniform: not changing in form or character; remaining the same in all cases and at all times uniform speed=constant speed speed is how fast an object is moving
An accelerating object is an object that has a change in velocity. Velocity is a vector—which has both magnitude and direction – a change in either the magnitude or the direction (or both) means there is a change in velocity. For this reason, it can be said that an object moving in a circle at constant speed is indeed accelerating. It is accelerating because the velocity is changing directions.
An object moving in a circle experiences an acceleration. This acceleration is directed TOWARD THE CENTER of the circle.
For an object moving in a circle, there must be an inward force acting upon it in order to cause its inward acceleration. This force is called the Centripetal Force. the word ‘centripetal’ means “center-seeking”
Newton's First Law of Motion (the Law of Inertia) states that…. "... objects in motion tend to stay in motion with the same speed and the same direction unless acted upon by an unbalanced force."
Centripetal Force: a physical force pushing or pulling the object towards the center of the circle. The word "centripetal" is merely an adjective used to describe the direction of the force. “center-seeking”
Examples of Centripetal Force As a car makes a turn, the force of friction acting upon the turned wheels of the car provide the centripetal force required for circular motion.
As the moon orbits the Earth, the force of gravity acting upon the moon provides the centripetal force required for circular motion.
As a bucket of water is tied to a string and spun in a circle, the force of tension acting upon the bucket provides the centripetal force required for circular motion.
Newton’s Second Law states that…. an object which experiences an acceleration must also be experiencing a net force. the direction of the net force always acts in the same direction as the acceleration.
The Centripetal Force causing an object to move in a circle creates an acceleration that is directed toward the center of the circle.
Equations to find Centripetal Acceleration: in other words where: v is velocity R is radius T is time and pi is 3.14
Find the Centripetal Acceleration of a runner running with a velocity of 8.8 m/s around a track with a radius of 25 m.
Find the Centripetal Acceleration of a car driving around an exit ramp with a velocity of 15 m/s. Assume the exit ramp has a radius of 30 m.
A dog sits 1.5 m from the center of a merry-to-round. The merry- go-round is set in motion, and the dog’s speed is 1.5 m/s. what is the dog’s centripetal acceleration?
A rope attaches a tire to an overhanging tree limb. A girl swinging on the tire has a centripetal acceleration of 3.0 m/s 2. If the length of the rope is 2.1 m, what is the girl’s speed?
A race car moving along a circular track has a centripetal acceleration of 15.4 m/s 2. If the car has a tangential speed of 30 m/s, what is the distance between the car and the center of the track?