Answer:
t = 376.99 s
Explanation:
We must solve this problem with the equations and kinematics, let's start by looking for the speed of the vehicle,
v = d / t
v = 7/40
v = 0.175 m / s
Since the speed e remains constant, we must find the length of the circle is
L = 2π r
L = 2π 21
L = 131.95 m
In the problem it does not specify clearly, but in general the curves of the road correspond to half a circle, so the length of the road is
L ’= L / 2
L ’= 131.95 / 2 = 65.97 m
as the speed is constant
t = L ’/ v
t = 65.97 / 0.175
t = 376.99 s
