Unit 3.1 Circular motion

Question 1

Define radian.

Answer 1

The angle subtended at the centre of a circle by an arc equal in length to the radius.

Question 2

Define angular speed, ω.

Answer 2

The rate of change of θ, i.e. the angle swept out by the radius per unit time.

Question 3

State the units for angular position, θ.

Answer 3

rad

Question 4

State the units for angular speed, ω.

Answer 4

rad s⁻¹

Question 5

Define angular speed, ω mathematically.

Answer 5

ω = Δθ / Δt

Question 6

State the formula for an angle in radians.

Answer 6

θ = length of arc (d) / radius of circle (r)

Question 7

State the formula for angular speed, ω relating to speed, v.

Answer 7

ω = speed (v) / radius of circle (r)

Question 8

Define period, T of circular motion.

Answer 8

Time taken for one complete revolution.

Question 9

Define frequency, F.

Answer 9

Number of revolutions per unit time.

Question 10

State the formula for frequency, f.

Answer 10

frequency = 1 / period

Question 11

State the formula for frequency, f in symbols.

Answer 11

f = 1 /T

Question 12

State the units for period, T.

Answer 12

Units: seconds (s)

Question 13

State the units for frequency, F.

Answer 13

Units: Hertz (Hz)/ s⁻¹

Question 14

State the formula for angular speed, ω relating to period, T.

Answer 14

ω = 2π / T

Question 15

State the formula for angular speed, ω relating to frequency, F.

Answer 15

ω = 2πf