Pls answer this question - Science - Force and Laws of Motion

Question

Pls answer this question

Vipra Mishra · Accepted Answer

Dear Student

The work done against gravity can be calculated from the increases
in height of the centre of mass

The centre of mass of a worm folded in two is located at the middle
of either half, i e , at a point one-quarter of the worm's total
length from one end, as given in the figure
<img alt="solution" src=
"https://haygot%20s3%20amazonaws%20com/questions/756599_741701_ans_695ea4f655924f6997527f6bc105a886%20jpg">
Thus, the centre of mass of the narrow flat worm travels 5cm up the
wall becuase its centre of mass is lies at 5cm
So distance covered by centre of mass to cover whole wall is 10-5 =
5 cm
Work done = mgh = 5mg
Now other worm moves 7 5cm on wall becuase its centre of mass lies
2,5 cm from each end
Hence distance travelled by worm's centre of mass to reach to top
is 10 - 2 5 = 7 5cm
Work done = mgh = 7 5 mg
So ratio of work done = work done by worm A/ Work done by B = 5/7 5
= 2/3 = 2:3

Regards