If you're listening to a sound that has a steady pitch, and suddenly the
pitch goes up, then you know that two things could have happened:
EITHER ...
-- The person or other source making the sound could have
raised the pitch of the sound being produced.
OR ...
-- The person or other source making the sound could have
started moving toward you.
OR ...
-- both.
Even if the pitch of the sound leaving the source doesn't change,
you would still hear it increase if the source starts moving toward
you. That's the so-called "Doppler effect".
Answer:
Explanation:
Given
Force 
one at an angle of
East of North and another at
West of North
Net Force is in North Direction

Forces in horizontal direction will cancel out each other
thus Work done will be by north direction forces

here 

All sources of energy on the planet (excluding nuclear reactions) are ultimately attributable to the sun. 'Fossil fuels' are derived from what once were living organisms, and all sources of food begin with primary producers (plants and algae which utilize photosynthesis).
Answer: Thats all I know about notes and rests, srry if this not what ur expecting.
Explanation: