Actually, the speed of the earth is the same everywhere, taking the angular speed as the valid measure of the speed
What does thrice mean not being mean or anything just saying so I can help with the question
<em>Important thing is that all unitless quantity is dimensionless quantity. .</em><em>A</em><em> dimensionless physical quantity may have an unit</em>
Answer:
Explanation:
Given
length of rope 
velocity while running 
when the person jumps off the bank and hang on the rope then we can treat the person as pendulum with Time period T which is given by




Greatest Possible distance will be covered when person reaches the other extreme end of assumed pendulum (velocity=zero)
therefore he must hang on for 0.5 T time
