Flashcards
Circular Motion
Cards in this deck (29)
- 1What is angular displacement?•The angle at which an object travels in circular motion with respect to the centre of its circular path.
- 2What are the units of angular displacement?•Radians or degrees.
- 3What is angular velocity?•The rate of change of angular displacement.
- 4What is the unit of Angular velocity?rads^-1
- 5What are the formulas for Angular velocity?ω = 2π/T
ω = 2πrf - 6Why do objects which undergo circular motion undergo centripetal acceleration?•When an object undergoes circular motion, its moving direction changes.
•Hence, the direction of the velocity of the object will change.
•Hence, the velocity will change.
•When velocity changes in a given time, the object accelerates. - 7What is linear velocity?•Velocity which has a tangential direction to an object which is undergoing circular motion.
- 8Why is the Centripetal force towards the centre of the circular path?•The direction of the centripetal acceleration is towards the centre.
•Therefore, according to Newton's second law, the direction of the resultant force will be in the direction of the acceleration. - 9What is significant of the Centripetal force?•It is the name given to the resultant force of an object which undergoes circular motion.
•It is NOT a type of force such as weight or friction. - 10What are the equations for centripetal force and acceleration? (4 equations)• F = mv^2/r
• F = mrω^2
• a = rω^2
• a = v^2/r - 11What are the applications of circular motion? (6 applications)•Motion of a celestial object.
•Vehicle taking a bend.
•Vehicle moving on a banked road (slanted road).
•Conical pendulum
•Vehicle moving on a bump
•Circular motion in vertical plane. - 12How can circular motion be investigated?•Attaching a rubber stopper to one end of a string and the other end through a glass tube.
•The end through the glass tube is used to hang slotted masses. - 13How is the radius kept constant?•A paper clip is attached to the end with slotted masses.
- 14How can readings be taken?•Rotate the bung until it starts to rotate in circular motion.
•Record the time taken to complete 15 revolutions.
•The period (T) can be calculated.
•Repeat two more times for the same mass and calculate the average period. - 15With respect to the glass rod experiment, how is the centripetal force provided?•The tension is greater than the weight of the masses.
•Therefore, a resultant force is present which is the centripetal force. - 16Why do we use slotted masses?•The slotted masses allow you to change the mass easily.
•Already having a known value for mass, without the need to measure it - 17How is a centripetal force provided in the motion of a celestial object?•The weight is the only force which acts on the celestial object.
•Therefore, the weight is the centripetal force. - 18How is a centripetal force provided in a vehicle taking a bend?•The inward friction between the tyres and the road surface is greater than the skidding of the vehicle.
•Vehicles tend to skid when they take bends.
•The inward friction provides the centripetal force. - 19According to circular motion, how can a car which takes a bend topple??•According to F=mv^2/r, a large velocity would mean a large centripetal force.
•If the centripetal force is greater than the maximum inward friction.
•Consequently, the vehicle will skid and topple. - 20How is a centripetal force provided for a vehicle moving on a banked road?•When a vehicle moves on a slanted road, a component of the normal reaction force is exerted.
•This component is towards the centre of the circular path.
•The component acts as the centripetal force. - 21In addition to the component of the normal reaction force, what is the other force which contributes to the centripetal force?•Inward friction.
•However, the inward friction is negligible compared to the component of the normal reaction force. - 22How is a centripetal force provided for a conical pendulum?•The bob moves in a horizontal circular path.
•Consequently, a resultant force is provided to the centre.
•The resultant force is provided by the horizontal component of the tension of the string. - 23How is a centripetal force provided for a vehicle moving on a bump?•Vehicle undergoes uniform circular motion.
•Centripetal force is provided by the cos component of the weight which is subtracted from the reaction force. - 24How can the passengers in the vehicle feel apparent weightlessness?•When a vehicle passes over a bump at a certain speed, it takes off.
•Consequently, it will lose contact with the ground.
•At this moment, the reaction force is zero. - 25How is a centripetal force provided for circular motion in a vertical plane? Ex: London Eye•As the object moves, its angular displacement (theta) changes.
•As its angular displacement changes, the tension in the string also changes.
•The tension provides the centripetal force.
•Centripetal force = T - weight compo. - 26When is the tension maximum and minimum in circular motion of a vertical plane?•Minimum at the highest point.
•Maximum at the lowest point.
•Therefore, the is a greater probability of the wire snapping at the lowest point. - 27Why do vehicles skid?•The force of friction between the tyres and the road is not enough to provide the centripetal force to keep it in a circle.
•Since no other force may also be acting as the centripetal force, the car skids. - 28How can the centripetal force be greater than the inward friction when the inward friction provides the centripetal force?•The inward friction may just be a component of the centripetal force.
- 29When an object undergoes circular motion in a vertical plane, can we say its angular displacement changes?•Angular displacement always changes for an object to be moving in a circle.
•Since the angle is changing (from 0 - 90 - 360 degrees), the angular displacement (how far away it is from the original angle) is changing
Information
- Description
- A-Level Physics Flashcards on Circular Motion, created by Jio Jenassi on 02/02/2016.
- Created by
- Jio Jenassi
- Views
- 1
- Rating