Definitions
what are mechanical waves?
waves that require a medium through which to travel
What does pitch mean?
It is the measure of how high or low a sound is perceived (it depends on frequency)
What is the equation to find λ ?
λ=v/f
What is the frequency of a wave with a wavelength of 5m and a velocity of 120m/s ?
f=V/lambda
f=120/5
It is 24 Hz
Why do we remove the negative sign from K (constant) hooke's law ?
because K is a scalar quantity not a vector quantity so it can't have a direction
what is a wavelength?
the distance between 2 adjacent similar points of a wave, such as from a crest to crest or trough to trough.
what is a destructive interference?
a superposition of 2 or more waves in which individual displacements on opposite sides of the equilibrium position are added together to form the resultant wave
what is Hooke's law equation? and their rearrangements
Fe=-kx
k=Fe/x
x=Fe/k
what is the frequency of a wave with 2m and 50m/s
f=v/λ
f=50/2
=25 Hz
what does relative motion create a change in?
a. amplitude
b. frequency
c. pitch
it is a frequency
what is crest and a trough?
A crest is the highest point over an equilibrium
A trough is the lowest point below an equilibrium
What is a standing wave?
a wave pattern that results when 2 waves of the same frequency, wavelength, and amplitude travel in opposite directions and interfere.
what is the equation for period in a simple pendulum?
T=2π√ L/ag
a load of 45N attached to a spring that is hanging vertically stretches the spring 0.14m. what is the spring constant?
Fe=-kx
k=Fe/x
K=45/0.14
k=321 N/m OR 3.2 x 102 N/m
how many dimensions do sound waves propagate in?
3 dimensions
what are nodes and anti nodes?
Nodes are the points where a complete destructive interference happen
Anti nodes are the points where the largest amplitudes are in
what is Doppler effect?
an observed change in frequency when there is relative motion between the source of waves and an observer
What is the equation of period in a mass spring?
T=2π√m/k
How much force is required to pull a spring 3.0cm from its equilibrium position if the spring constant 2.7 x 103 N/m?
Fe=-kx
3cm=0.03m
Fe=2700(0.03)
Fe=81N
how does a constructive interference move?
in the same directions
what is simple harmonic motion?
Vibration about an equilibrium position in which a restoring force is proportional to the displacement to the displacement from equilibrium
what is a medium?
a physical environment through which a disturbance can travel
equation of frequency
f=1/T
To launch a ball, a pinball machine compresses a spring 4.0cm. The spring constant is 13 N/m. What is the force on the ball when the spring is released?
Fe=-kx
4cm=0.04m
Fe=13 x 0.04
Fe =0.52N
what is the angle for a simple pendulum to have a simple harmonic motion?
a simple pendulum has to have 15o angle to have a SHM