<span>b. The coefficient of static friction for all contacting surfaces is μs=0.35. neglect friction at the rollers.
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The correct answer is D: which is none of the above.
Hint: a wreckling ball contains pontential energy that acts like a pendulum
a pot of water contains pontential thermal energy
Least count of the pulse stopwatch is given by

this means each division of the stopwatch will measure 0.1 s of time
After 3 journeys from one end to other we can see that total time that is measured here is shown by the clock as 52nd division
So here total time is given as
Time = (Number of division) (Least count)
now we will have


Designing warning and evacuation systems could be a step in a plan designed to mitigate the negative impacts of a natural hazard.