Final answer:
The average velocity of the black mumba snake for the complete trip is 6.4 km/h.
Step-by-step explanation:
To find the average velocity for the complete trip, we need to calculate the total displacement and divide it by the total time taken. In this case, the snake initially moves forward for 2.3 seconds and then returns back to its hideout in 12 seconds. The displacement during the forward motion is given by distance = velocity x time = 18 km/h x 2.3 s = 0.0417 km. During the return motion, the displacement is in the opposite direction, so it will be negative: displacement = -18 km/h x 12 s = -0.216 km. Thus, the total displacement is 0.0417 km - 0.216 km = -0.1743 km. The total time taken for the complete trip is 2.3 s + 12 s = 14.3 s.
To find the average velocity, we divide the total displacement by the total time taken: average velocity = total displacement / total time = -0.1743 km / 14.3 s. Converting the velocity to km/h: average velocity = (-0.1743 km / 14.3 s) x (3600 s / 1 h) = -1.36 km/h (rounded to two decimal places). Since average velocity is a scalar quantity, we take the magnitude, which is 1.36 km/h (rounded to two decimal places). The answer is therefore option c) 6.4 km/h.