To solve this problem, we can use the relationship between acceleration, velocity, and radius in circular motion:
a = v^2 / r
where: a is the centripetal acceleration, v is the instantaneous velocity, and r is the radius of the circular road.
Given: Acceleration (a) = 4 m/s^2 Radius (r) = 20 m
We need to find the instantaneous velocity (v) at this point.
Rearranging the formula, we have:
v = √(a * r)
Substituting the values:
v = √(4 m/s^2 * 20 m) v = √(80 m^2/s^2) v ≈ 8.94 m/s
Therefore, the instantaneous velocity of the automobile at that point is approximately 8.94 m/s.