A-level Physics: Circular Motion (Topic 5.3)

Centripetal force

v = 2πr / t or v = ωr

a = v² / r or a = ω²r

<p>F = mv² / r or F = mω²r</p> Signup and view all the answers

<p>Gravitational fields, friction, tension in a rope, etc.</p> Signup and view all the answers

<p>Because the centripetal force is the net force acting towards the centre of the circle.</p> Signup and view all the answers

<p>By tying a bung to a piece of string and threading it through a glass tube, with a weight suspended from the other end.</p> Signup and view all the answers

<p>It provides the centripetal force, F = Mg, through the tension in the string.</p> Signup and view all the answers

<p>F = mω²r</p> Signup and view all the answers

<p>A radian is the angle subtended by a circular arc with a length equal to the radius of the circle.</p> Signup and view all the answers

<p>Divide the angle by 360 and then multiply by 2π.</p> Signup and view all the answers

<p>The time, in seconds, taken for an object to travel a full circle.</p> Signup and view all the answers

<p>f = 1/T</p> Signup and view all the answers

<p>rads^-1</p> Signup and view all the answers

<p>ω = θ/t</p> Signup and view all the answers

<p>Because its direction is constantly changing.</p> Signup and view all the answers

<p>To keep the object moving in a circle.</p> Signup and view all the answers

<p>ω = 2π/T</p> Signup and view all the answers

<p>The velocity of an object moving in a circle is constantly changing, and this change in velocity is provided by the centripetal acceleration.</p> Signup and view all the answers

<p>The centripetal force acts perpendicular to the direction of the velocity, towards the centre of the circle.</p> Signup and view all the answers

<p>The centripetal force is proportional to the mass of the object and inversely proportional to the radius of the circle.</p> Signup and view all the answers

<p>The weight provides the necessary centripetal force to keep the object moving in a circle.</p> Signup and view all the answers

<p>Because the centripetal force is the net force acting towards the centre of the circle, and multiple forces may act on the object.</p> Signup and view all the answers

<p>Friction can be a source of centripetal force, providing the necessary force to keep the object moving in a circle.</p> Signup and view all the answers

<p>The angular velocity is a measure of how fast the object is moving around the circle, and it is related to the centripetal acceleration and force.</p> Signup and view all the answers

<p>This formula relates the centripetal force to the mass of the object, its velocity, and the radius of the circle, and is a fundamental concept in circular motion.</p> Signup and view all the answers

<p>The period of the object is inversely proportional to its angular velocity.</p> Signup and view all the answers

<p>The radius of the circle is used as the length of the circular arc to define a radian.</p> Signup and view all the answers

<p>The velocity of an object moving in a circle is constantly changing because its direction is constantly changing, and velocity is a vector quantity that has both magnitude and direction.</p> Signup and view all the answers

<p>The period and frequency are inversely proportional, with the formula f = 1/T.</p> Signup and view all the answers

<p>The angular velocity is the rate of change of angle, given by the formula 𝜔𝜔 = 𝜃𝜃/𝑡𝑡.</p> Signup and view all the answers

<p>The centripetal force is responsible for keeping the object moving in a circle, by constantly changing its direction.</p> Signup and view all the answers

<p>The unit of angular velocity is rads-1 because it is the rate of change of angle, measured in radians, per unit time.</p> Signup and view all the answers

<p>The formula relates the angular velocity to the period of an object moving in a circle, showing that the angular velocity is inversely proportional to the period.</p> Signup and view all the answers

<p>The angular velocity is related to the frequency by the formula 𝜔𝜔 = 2𝜋𝜋𝑓𝑓.</p> Signup and view all the answers

<p>The centripetal force acts towards the centre of the circle, which allows the object to maintain its circular path.</p> Signup and view all the answers