circular motion Flashcards
how do you convert from degrees to radians
divide by 360 then multiply by 2Pi
period of an object in circular motion
the time taken for one full rotation
what is angular velocity
angle travelled through divided by the time taken
similar to linear speed except we are interested in the rate of rotation rather than distance/time
what kind of force is required to keep an object moving in a circle at constant speed
centripetal force
what is a centripetal force
a force applied always towards the centre of that circle
are centripetal force and velocity of an object moving in a circle always in the same direction
no, velocity is always at a tangent to the circle, force is always along the radius, they are perpendicular
how are linear and angular velocity related
v = wr
w = angular velocity
r = radius
an object moving in a circle at a constant speed is not accelerating. true or false
false, the direction is always changing hence the velocity always changing which means it is accelerating
what equation gives acceleration in terms of angular velocity
a = w^2r
what is acceleration in terms of linear velocity
a = v^2/r
what are the equations for centripetal force
f = mv^2/r
f = mw^2r
describe the steps how one can investigate circular motion via an experiment
- tie a bung with mass m to a piece of string, and threading it through a glass tube
- the other end of a string has a weight, with mass M suspended from it. this provided the centripetal force F = mg as the tension throughout the string is constant
- the string is whirled in a. circle and the time taken for a complete rotation is recorded
- the mass of the weight is altered and the experiment is repeated
- equate mg and centripetal force
- mv^2/r = mg
-by measuring the radius of the circle and using the time for one complete oscillation the velocity can be determined - when v^2 is plotted against M a straight line graph which passes through the origin should be produced
