13. Oscillations

Question 1

Definition of Simple Harmonic Motion

Answer 1

Restoring force/acceleration is proportional to displacement and always acts in opposite direction of displacement/ towards equilibrium position

Question 2

Definition for resonance

Answer 2

Resonance occurs when driving frequency of (object A) is equal to the natural frequency of (object B) so there is maximum energy transfer

Question 3

Model answer for resonance

Answer 3

• Object A forces oscillation on Object B
• Natural freq of object B is …
• Driving frequency of forced oscillation is equal to natural freq of object B
• Resonance occurs
• There is maximum energy transfer to object B
• Resulting in an increase in the amplitude of oscillations of Object B.

Question 4

What is damping?

Answer 4

Damping reduces size of oscillation at resonance. Max ampl still reached but is a lower value

Question 5

Model Answer - Damping

Answer 5

• Energy is transferred away from the oscillating system to the damping system
• This energy is dissipated in the damping system
• Causing a decrease in amplitude of oscillations

Question 6

Model Answer - Total energy of SHM object

Answer 6

• Total energy of system stays constant
• Potential energy transferred to KE as object moves towards the equilibrium position
• KE; 0 at max displacement; max KE at equilibrium
• PE; 0 at equilibrium position, max at max displacement

Question 7

Describe procedure student used to obtain an accurate value of T (2)

Answer 7

• Record time period for x no of oscillations and divide by x
• Time oscillations from equilibrium position of bob using fiducial marker
• Repeat timings for multiple oscillations and calculate mean