A ball is dropped from rest from a height of $1 \: m$ in a frictionless tube as shown in the figure. If the tube profile is approximated by two straight lines (ignoring the curved portion), the total distance travelled (in $m$) by the ball is _____ (correct to two decimal places)

Reason: because it is asked to find the distance travelled while all the contact surfaces are assumed frictionless.

In the solution, the distance of ball is calculated only till the ball first goes down in the vertical tube then goes up in the inclined tube.

Will the ball not come down?
140 points 3
3

If ball comes down due to gravity the answer will be 3.8
@susmit Why will the ball ever stop. After comimg down( i.e. travelling 3.8m ) it will again go up by 1m in vertical tube then again come down. This will go on to happen infinite times.

This question has ambiguous language and marks should be given to all
I think there is some error while calculating the average of top 0.1% candidate in a session.
As I checked just now and found that average of top.1% was 84.00  for set 2 and total candidates who have checked till now for session 2 are 22527 which means in 0.1% there will be 23 candidates. Now from 90-95 there are 5 candidates while from 85-90 there are 27 candidates so if the average of top 23 candidates will be taken then it will be more than 85 but there it is 84.00
Top 0.1% is estimated for actual number if students, not the sample size.
sir revise answer key in gate overflow as this question is provided marks to all.
140 points 2
2

It is updated