3.6.1 Periodic Motion

Question 1

what is a radian

Answer 1

a unit for measuring angles
there are 2π radians in one full circle

Question 2

what does motion in a circular path at constant speed imply

Answer 2

there is an acceleration and requires a centripetal force

Question 3

what is the formula for the magnitude of angular speed

Answer 3

ω = v/r = 2π f

Question 4

what is the formula for centripetal acceleration

Answer 4

a = v^2 /r = ω^2 r

Question 5

what is the formula for centripetal force

Answer 5

F = m v^2 / r = m ω^2 r

Question 6

in what direction is centripetal acceleration for circular motion

Answer 6

towards the centre (of the circle)

Question 7

in what direction does the centripetal force act

Answer 7

towards the centre (of the circle)

Question 8

what is simple harmonic motion

Answer 8

any motion in which the acceleration is directed towards a fixed point and is directly proportional to the negative of the displacement.

Question 9

what is the equation for SHM

Answer 9

a = − ω^2 x

Question 10

what are the characteristics of a displacement-acceleration graph

Answer 10

straight line graph
passes through the origin

Question 11

what is the gradient of a displacement-acceleration graph

Answer 11

angular speed (angular frequency)
gradient = −ω^2
ω= (−gradient)^1/2
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