Answer: This is called the Doppler effect, where waves shift frequency and wavelength as the source travels towards you (higher frequency, shorter wavelength) or away from you (lower frequency, longer wavelength)
Explanation:
hoped this helped have a good day :)
Answer:
I think answer is zero
bcz momentum=mass×velocity
body was initially at rest it means its velocity is zero
30×0=0
Answer:

Given:
Radius of curvature (R) of a spherical mirror = 20
To Find:
Focal length (f)
Explanation:
Formula:

Substituting value of R in the equation:



Answer:

Explanation:
From the question we are told that:
Pressure of 
Bottle cap area 
Generally the equation for Resultant pressure
is give as is mathematically given by

Where



Generally the equation for Force exerted by screw F is give as is mathematically given by

