Answer :
Final answer:
The work done in keeping the rod vertical with one of its ends touching the ground is 392 J. The correct option is B .
Explanation:
To calculate the work done in keeping the rod vertical with one of its ends touching the ground, we need to determine the change in potential energy. When the rod is lying horizontally on the ground, its center of mass is at a height of zero. When it is vertical with one end touching the ground, its center of mass is at a height of 2 meters. The work done is equal to the change in potential energy, which can be calculated using the formula:
Work = mgh
where m is the mass of the rod, g is the acceleration due to gravity, and h is the change in height.
Given that the mass of the rod is 20 kg and the change in height is 2 meters, we can calculate the work:
Work = (20 kg)(9.8 m/s^2)(2 m) = 392 J
Therefore, the work done in keeping the rod vertical with one of its ends touching the ground is 392 J.
The work done in keeping the rod vertical with one of its ends touching the ground is 392 J.
