Simple Harmonic Motion

Question 1

What is simple harmonic motion?

Answer 1

An oscillation in which the restoring force and acceleration are always directly proportional to the displacemnt from the midpoint and directed towards the midpoint

Question 2

How does the restoring force do work?

Answer 2

transferes energy from potential to kinetic and back again

• when moving away it gains pe so slows until no ke and changes direction
• total energy is always the same

Question 3

What doesnt depend on amplitude?

Answer 3

Frequnecy and period

Question 4

Whats the equation if someone starts stowatch at max displacement?

Answer 4

Cos

Question 5

Whats the equation if someone starts stop watch at mid point (no displacement)?

Answer 5

Sin

Question 6

Connection between velocity and angular frequency?

Answer 6

WA

Question 7

How to experimentally determine time period equatuon for spring?

Answer 7

1. Pull spring set ampliture
2. use position sensor to measure displacement w time and read of period T
3. change masses
4. change k (springs as in parralel)
5. ch age A by pulling different amounts
6. Deduce T^2 proportional to m
7. T^2 inversly proportional to k
8. T independant of A

Question 8

How to experimentally determine time period with pendulum?

Answer 8

1. set up bob on string with protractor
2. pull bob to small angle and posision eye level w reference mark start watch
3. record time for 1 period (passes mark left to right) to get T
4. if T too small take am average over multiple periods
5. vary l and m and angle
6. T^2 proportional to L indepentdant of m and Angle
7. Improve w angle sensor and data logger

Question 9

Whats a free vibration? W equation

Answer 9

No energy transfeered so oscillater w same amplitude forever

1/2kA^2 (horizontal)

Question 10

Whats the driving frequency?

Answer 10

Forced vibrations from external forces frequency is called the driving frequency

Question 11

Whats the natural frequency?

Answer 11

Frequency of Oscillation with no external forces

Question 12

What’s resonance?

Answer 12

When the driving frequency approaches the natural frquency there is a rapidle increasing amplitude

Question 13

Whats dampning?

Answer 13

Energy lost to surroundings usually due to frictional forces

Question 14

Whats critical dampning?

Answer 14

Reduces amplitude to zero in shortest time possible

Question 15

Whats overdamping?

Answer 15

Take longer to reduce amplitude than critical dmapning

Question 16

How does damping affect resonance

Answer 16

Lightly damping gives sharp resonance peak

Heavily damoung gives flatter peak as not as sensitive to drivijg frequency