Question

I want important notes and equations in physics 1
Related topics:

chapter 6 :

topic:

1. description of uniform circular motion

2. radial acceleration

chapter 7:

topic:

1. unbanked and banked curves

2. angular acceleration

Answer 1

Chapter 6

1)Uniform circular motion can be described as the motion of an object in a circle at a constant speed. As an object moves in a circle, it is constantly changing its direction. At all instances, the object is moving tangent to the circle. Since the direction of the velocity vector is the same as the direction of the object's motion, the velocity vector is directed tangent to the circle as well. The animation at the right depicts this by means of a vector arrow.

An object moving in a circle is accelerating. Accelerating objects are objects which are changing their velocity - either the speed (i.e., magnitude of the velocity vector) or the direction. An object undergoing uniform circular motion is moving with a constant speed. Nonetheless, it is accelerating due to its change in direction. The direction of the acceleration is inwards. The animation at the right depicts this by means of a vector arrow.

The final motion characteristic for an object undergoing uniform circular motion is the net force. The net force acting upon such an object is directed towards the center of the circle. The net force is said to be an inward or centripetal force. Without such an inward force, an object would continue in a straight line, never deviating from its direction. Yet, with the inward net force directed perpendicular to the velocity vector, the object is always changing its direction and undergoing an inward acceleration.

2) Let's say an object is tied at A, one end of a string OA and rotated keeping the other end O as center. When the string is rotated fast, the string gets completely stressed out and the length of the string becomes the radius of rotation. It means a force is exerted on the object from the center to the end and there by an acceleration ao in a radial direction is faced by the object. To counter this force, a tension force develops in the string acting in the opposite direction. This tension force is called the centripetal force and the acceleration generated on the object is called the radial acceleration and denoted as ar.

a = v^2/R where v is the tangential velocity and R is the radius of the circle.