Manomay conducted an experiment where 4 identical
metal balls were allowed to roll down 4 similar curves
with surfaces of different texture. The time taken for
the ball to come to a complete stop for each of the
different surfaces was recorded in the table below.
Which curve has the roughest surface?
A P
B Q
C R
D S
How can the roughest surface allow lesser stopping time? Answer to this question should be R. Please advise