Question

please solve as soon as possible

Answer 1

Time taken to complete one revolution is 40s
Number revolutions occurs in 2min 20s (= 140s) is 140/40 = 3.5

Therefore,
3 revolutions + 1/2 revolutions takes place in 140s
Displacement after three revolutions = 0
Displacement after 1/2 revolution = 2r (where r is radius of circle)
Total displacement after 140s = 2r

Distance travelled after 3 revolutions = 3*2πr = 6πr
Distance travelled after 1/2 revolution = πr
Total distance after 140s = 6πr + πr = 7πr

Ratio of displacement and distance after 140s = 2r / (7πr)
= 2/(7π)
= 2 / (7 * 22/7)
= 2/22
= 1/11