Circular Motion: Circular Motion
PowerPoint Presentation: Start Stop Click here Circular Motion We come across many things in our daily life that are moving along circular path. Take a small stone. Tie it at one end of a string and keep the other end of the string in your hand as shown in figure Now rotate the stone holding the string. The stone will move in a circular path. The motion of stone will be called as circular motion.
PowerPoint Presentation: Circular Motion Now rotate the stone holding the string. The stone will move in a circular path. The motion of stone will be called as circular motion. We come across many things in our daily life that are moving along circular path. Take a small stone. Tie it at one end of a string and keep the other end of the string in your hand as shown in figure
PowerPoint Presentation: Similarly, motion of the moon around the Earth is circular motion. The motion of an object in a circular path is known as circular motion. Circular Motion
PowerPoint Presentation: v v Consider a body tied at the end of a string moving with uniform speed in a circular path. A body has the tendency to move in a straight line due to inertia. Then why does the body move in a circle? Centripetal Force
PowerPoint Presentation: v v F c v v The string to which the body is tied keeps it to move in a circle by pulling the body towards the centre of the circle. The string pulls the body perpendicular to its motion as shown in figure. This pulling force continuously changes the direction of motion and remains towards the centre of the circle. This centre seeking force is called the centripetal force. It keeps the body to move in a circle. Centripetal force always acts perpendicular to the motion of the body . Centripetal force is a force that keeps a body to move in a circle Centripetal Force
PowerPoint Presentation: v v T v v Let us study the centripetal forces in the following examples: i . Figure shows a stone tied to one end of a string rotating in a circle. The tension in the string provides the necessary centripetal force. It keeps the stone to remain in the circle. If the string is not strong enough to provide the necessary tension, it breaks and the stone moves away along a tangent to the circle as shown Centripetal Force
PowerPoint Presentation: F c F c ii . The moon revolves around the Earth. The gravitational force of the Earth provides the necessary centripetal force . Centripetal Force
PowerPoint Presentation: v v F c m v v Centripetal acceleration a c = v 2 r According to Newton’s second law of motion, the centripetal force F c is given by F c = m a c F c = m v 2 r Equation shows that the centripetal force needed by a body moving in a circle depends on the mass m of the body, square of its velocity v and reciprocal to the radius r of the circle Let a body of mass m moves with uniform speed v in a circle of radius r. The acceleration a c produced by the centripetal force F c is given by r Centripetal Force
PowerPoint Presentation: v v F c m v v r Centripetal Force Consider a stone as shown is tied to a string moving in a circle. The necessary centripetal force acts on the stone through the string that keeps it to move in a circle. According to Newton’s third law of motion, there exists a reaction to this centripetal force. Centripetal reaction that pulls the string outward is sometimes called the centrifugal force
PowerPoint Presentation: Consider a stone as shown is tied to a string moving in a circle. The necessary centripetal force acts on the stone through the string that keeps it to move in a circle. According to Newton’s third law of motion, there exists a reaction to this centripetal force. Centripetal reaction that pulls the string outward is sometimes called the centrifugal force . v v F c F g m v v Centrifugal Force
PowerPoint Presentation: Start Stop Click here While the coaster cars move around the loop, the track provides centripetal force preventing them to move away from the circle Do You Know ?
PowerPoint Presentation: The dryer of a washing machine is basket spinners. They have a perforated wall having large numbers of fine holes in the cylindrical rotor as shown in figure . The lid of the cylindrical container is closed after putting wet clothes in it. When it spins at high speed, the water from wet clothes is forced out through these holes due to lack of centripetal force Click the green to start & red to stop Double click the green to restart Conceptual Physics ASHFAQ AHMAD SABER Centrifugal Force
PowerPoint Presentation: This problem is solved by banking of curved roads. Banking of a road means that the outer edge of a road is raised. Imagine a vehicle on a curved road such as shown in figure. Banking causes a component of vehicle’s weight to provide the necessary centripetal force while taking a turn. Thus banking of roads prevents skidding of vehicle and thus makes the driving safe. banking of curved roads When a car takes a turn, centripetal force is needed to keep it in its curved track. The friction between the tyres and the road provides the necessary centripetal force. The car would skid if the force of friction between the tyres and the road is not sufficient enough particularly when the roads are wet. Radius of the circular track Banking of roads Start Click here
PowerPoint Presentation: This problem is solved by banking of curved roads. Banking of a road means that the outer edge of a road is raised. Imagine a vehicle on a curved road such as shown in figure. Banking causes a component of vehicle’s weight to provide the necessary centripetal force while taking a turn. Thus banking of roads prevents skidding of vehicle and thus makes the driving safe. Banking of roads Radius of the circular track banking of curved roads
PowerPoint Presentation: Most modern plants use a separator to control the fat contents of various products. A separator is a high-speed spinner. It acts on the same principle of centrifuge machines. The bowl spins at very high speed causing the heavier contents of milk to move outward in the bowl pushing the lighter contents inward towards the spinning axis. Cream or butterfat is lighter than other components in milk. Therefore , skimmed milk, which is denser than cream is collected at the outer wall of the bowl. The lighter part (cream) is pushed towards the centre from where it is collected through a pipe