Ch17 simple harmonic motion

Question 1

What are the 2 conditions for simple harmonic motion?

Answer 1

• acceleration is proportional to displacement
  F=kx
  ma=kx
  a= k/m X x
• acceleration is always directed towards equilibrium:
  negative gradient, acceleration and displacement in opposite directions

Question 2

displacement equations in simple harmonic motion.

Answer 2

x=Acos(wt) when oscillating object start from maximum displacement
x=Asin(wt) when oscillating object start from zero displacement

Question 3

What are the graphs in simple harmonic motion?

Answer 3

displacement against time:
- cos graph
velocity against time:
- -sin graph
acceleration against time:
- -cos graph

Question 4

Velocity in simple harmonic motion

Answer 4

x=-A x=0 x=A

V= +-w √A^2-x^2

When x=A
V=0
When x=-A
V=0
When x=0
V is max

Vmax=wA

Question 5

kinetic energy in energy against displacement graph:

Answer 5

x=A x=0 x=-A

at x=A and x=-A:
kinetic energy = 0
at x=0:
kinetic energy = max

Question 6

potential energy in energy graph against displacement

Answer 6

x=A x=0 x=-A
at x=A and x=-A:
potential energy = max
at x=0:
potential energy=0

Question 7

Period dependence on amplitude experiments.
equipment:

Answer 7

-stand
-mass
-spring
-stop clock
-fiducial marker

Question 8

Period dependence on amplitude experiments.
procedure:

Answer 8

-place fiducial marker at equilibrium
-measure original length of the spring
-measure length of the spring before realising it (this length is the amplitude)
-release the spring to initiate SHM
-time 10 oscillation to reduce uncertainty
- divide by 10 to get 1 time period
- repeat with multiple amplitude

Question 9

Period dependence on amplitude experiments.
conclusion:

Answer 9

in SHM, time period is independent of amplitude.