Answer:
Convection is the transfer of thermal energy from one place to another by the movement of gas or liquid particles. How does this happen? As a gas or liquid is heated, the substance expands. This is because the particles in liquids and gases gain kinetic energy when they are heated and start to move faster.
Answer:
f>1000Hz and wavelength=0.343 m
Explanation:
We are given that
Frequency of stationary siren,f=1000 Hz
Wavelength of stationary sound,
When a observer is moving towards the siren then the frequency increases.
Therefore,an observer who is moving towards the siren measure a frequency >1000 Hz.
The wavelength depends upon the speed of source.
But we are given that siren is stationary.
Therefore, source is not moving and then the wavelength remains same.
f>1000Hz and wavelength=0.343 m
Answer:
= 391.67 Hz
Explanation:
The sound of lowest frequency which is produced by a vibrating sting is called its fundamental frequency (
).
The For a vibrating string, the fundamental frequency (
) can be determined by:
= 
Where v is the speed of waves of the string, and L is the length of the string.
L = 42.0 cm = 0.42 m
v = 329 m/s
= 
= 
= 391.6667 Hz
The fundamental frequency of the string is 391.67 Hz.
Answer:
v_average = 15 m / s
Explanation:
The average speed can be found in two ways,
* taking the distance traveled and divide it by the time spent
* taking the velocities in each time interval and then finding the weighted average by the time fraction
v_average = 1 / t_total ∑
vi ti
Let's apply this last equation
Total time is
t = t₁ + t₂
t = 10 + 10 = 20 min
v_average = 10/20 10 + 10/20 20
v_average = 10/2 + 20/2
v_average = 15 m / s