Simple Harmonic Motion

Question 1

Define simple harmonic motion

Answer 1

-acceleration/ force propotional to displacement from a fixed point
-acceleration and displacement in opposite direction

Question 2

What is meant by oscillations

Answer 2

to-and-fro/ backward and forward motion between 2 limits

Question 3

What is meant by free oscillations
(4 ans)

Answer 3

-no energy loss or gain/ no external force acting/ constant energy/ constant amplitude

Question 4

What is meant by resonance

Answer 4

-large/ maximum amplitude of vibration
-when impressed frequency equals to natural frequency of vibration

Question 5

State and explain one situation where resonance is useful

Answer 5

-vibration of quarts/ piezoelectric crystal
-for accurate timing or maximise amplitude of ultrasound waves

Question 6

State and explain one situation in which resonance should be avoided

Answer 6

> metal panels on machinery vibrate
-motor in machine impressed frequency on panel

> car suspension system vibrates/ oscillates
-going over bumps would give large amplitude vibrations

Question 7

For an oscillating body, state what is meant by:
forced frequency

Answer 7

frequency at which object is made to vibrate/ oscillate

Question 8

For an oscillating body, state what is meant by:
natural frequency

Answer 8

frequency at which object vibrates when free to do so

Question 9

For an oscillating body, state what is meant by:
resonance

Answer 9

maximum amplitude of vibration of oscillating body
when forced frequency equals natural frequency

Question 10

State one situation resonance should be avoid and how to reduce

Answer 10

-vibrating metal panels
-either place strengthening struts across the panel or change shape/ area of panel

Question 11

What is meant by damping

Answer 11

-Loss of energy
-reduction of amplitude
-due to the force acting in opposite direction of the motion/ friction / resistive forces