The correct answer is - a. was a sign of danger.
Once the people saw that the ocean waters are receding and were living vast space without water behind them, they knew that something big and very dangerous will happen. And in fact it did. The water that was sucked in in the place were there was a crack on the ocean floor, got shot back under big pressure and it had very big speed, as well as having waves that were destroying anything on their way.
FIrst let's convert the angular distance covered by the wheel into radians. We know that
Therefore, 2 revolutions correspond to
The average angular speed of the wheel is given by the ratio between the angular displacement and the time taken:
where in our problem,
and t=4.0 s, so the angular speed of the wheel is
Answer
given,
copper rod length = 50 cm
density of the copper = 8.92 g/cm³
iron rod length = 50 cm
density of iron = 7.86 g/cm³
mass of iron = density × volume
m_i = 7.86 × A × l/2
m_c = 8.96 × A × l/2
taking the intersection of copper and iron rod be starting point cooper side is taken as positive side and iron side length is taken to be -ve side.
center of mass
=
=
=
=
= 0.015793 m
= 1.579 m (+ve)
center of mass shift to cooper because cooper is heavy.