Further mechanics (Periodic Motion)

Question 1

Angular velocity, ω

Answer 1

the rate of change of angular displacement per unit time, t

Question 2

Frequency

Answer 2

The frequency f of an object in circular motion is the number of complete revolutions made by the object per per second, Hertz

Question 3

Period, T

Answer 3

The period T of an object in circular motion is the time taken for the object to make one complete revolution.

Question 4

Simple Harmonic Motion

Answer 4

An oscillation in which the acceleration of the object is directly proportional to its displacement from the equilibrium position and is directed towards equilibrium.

Maximum velocity occurs at the centre of oscillation (equilibrium).
Maximum acceleration occurs at the maximum displacement.

Question 5

Natural frequency, Forced Vibrations and resonance

Answer 5

The frequency a system freely vibrates at after being given a single impulse.
Vibrations are forced when a periodic driving force is applied and the frequency is determined by the frequency of the driving force.
Resonance occurs when the frequency of the applied driving force is equal to the natural frequency.

Question 6

Damping, Critical damping, Overdamping, Underdamping

Answer 6

Damping occurs when an opposing force dissipates energy to the surroundings with each oscillation.
Critical damping reduces the amplitude
to zero in the quickest time.
Overdamping is when the damping force is too strong and it returns to equilibrium slowly without oscillation.
Underdamping is when the damping force is too weak and it oscillates with exponentially decreasing amplitude.

Question 7

Why does circular motion have acceleration even though the speed is constant?

Answer 7

Speed is a scalar and velocity is a vector. The object keeps changing direction so the velocity changes. Acceleration is the rate of change of velocity so it accelerates towards the centre.

Question 8

Using the simple pendulum to calculate g techniques?

Answer 8

Fiducial marker at equilibrium, transit speed fastest.
Eye level
Count down of 3 before starting
Time for 30 oscillations and then find the mean and do repeats.

Question 9

Calculating spring constant techniques?

Answer 9

Fiducial marker at equilibrium, transit speed fastest.
Eye level
Count down of 3 before starting
Time for 30 oscillations and then find the mean and do repeats.
Counterweight at camp or G clamp.
Electric balance to measure mass.