Question

derived expression for escape velocity of satellite state Doppler effect in sound.​

Answer 1

Answer:

Escape velocity is the minimum Velocity with which a satellite can be projected such that it goes out of the gravitational Field of the planet.

It means that the Kinetic energy and Potential energy of the satellite becomes zero. ( i.e the satellite reaches zero)

$\sf{KE1 + PE1 = KE2 + PE2 }$

$\sf{ \implies \: \dfrac{1}{2} m {v}^{2} - \dfrac{GMm}{r} = 0 + 0}$

$\sf{ \implies \: \dfrac{1}{2} m {v}^{2} = \dfrac{GMm}{r} }$

$\sf{ \implies \: v = \sqrt{ \dfrac{2GM}{r} } }$

This represents the fact that escape Velocity doesn't depend on the mass of the satellite.

It depends on :

• Mass of Planet
• Radius of Planet

Escape Velocity in case of Earth ( from the surface) is that of 11.2 km/sec.

$\boxed{ \sf{ \large{ \blue{Doppler's \: Effect}}}}$

This effect states the change in frequency ( apparent frequency) with movement of observer in relation to the source.

For example , if observer is moving towards the source , the observer listens to a higher apparent frequency as compared to the actual frequency of the source.