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:
According to Hook's law, we know,
strain/stress =Constant
Explanation: So, the ratio between stress and strain is always constant.
So, if stress is increased, then strain changes in that way so that this ratio always remains constant.
Answer: 
Explanation:
Given
Length of the race track 
the radius of curvature of the track 
time taken to run on track is 
Speed of runner is
Centripetal acceleration is
Tom llega primero a la superficie de el lago
