Answer:
Ac = v²/r
where, Ac is centripetal acceleration
v is velocity
r is radius
5 = (20)²/r
r = 400/5
r = 80m
from,
w = 2πf
where, w = angular velocity and f frequency
w = v/r
f = n/T
then,
v = 2πrn ,n = 1 to complete 1 cycle
T
T = 2πr/v
T = 2π*80/20
T = 25.14seconds.
The car would take 25.14s to complete 1 cycle of the roundabout.
