Phys - Vibrations

Question 1

Simple Harmonic Motion

Answer 1

Periodic motion of a body due to a restoring force which is proportional to its displacement from a fixed equillibrium point and always points in the opporite direction from said displacement.

Question 2

Resonance

Answer 2

Forced oscillation due to a driving force at a fixed frequency, which dictates the amplitude the SHM system will oscillate at.

Question 3

Damping - Light

Answer 3

Amplitude progressively decreases over time due to a resistive force, but period remains the same

Question 4

Damping - Heavy

Answer 4

An object asymptotically approaches the fixed equillibrium point, due to a resistive force.

Question 5

Damping - Critical

Answer 5

An object takes the smallest amount of time possible to get to 0 (quarter of an oscillation), due to a resistive force

Question 6

Damping

Answer 6

Energy is dissapated from an SHM system, leading to a reduction in amplitude

Question 7

Practical Damping Example

Answer 7

Vehicle suspension systems use critical damping to minimise the oscillation and avoid large amplitudes of the vehicle, returning to a stable equillibrium as quickly as possible.

Question 8

Useful Resonance Example

Answer 8

The microwave oven’s cavity resonates at the frequency of the mixrowaves generated, keeping in energy more efficiently.

Question 9

Not Useful Resonance Example

Answer 9

Bridges experience periodic forces like footsteps or wind, which can match the resonant frequency of the bridge’s material and cause it to oscillate at an unsafe amplitude.

Question 10

Centripetal Acceleration

Answer 10

The direction of the velocity is changing over time, leading to an acceleration

Question 11

Car Safety

Answer 11

Banking from contribution of normal force

Question 12

Resonance Graph

Answer 12

More damping -> lower graph