Question

The black mamba is one of the world’s most poisonous snakes, and with a maximum speed of 18.0 km/h, it is also the fastest. Suppose a mamba waiting in a hide-out sees prey and begins slithering toward it with a velocity of +18.0 km/h. After 2.50 s, the mamba realizes that its prey can move faster than it can. The snake then turns around and slowly returns to its hide-out in 12.0 s. Calculate the mamba's average velocity for the complete trip.​

Answer 1

From hide-out toward prey:

Speed = 18 km/hr=5 m/s. ... Time = 2.5 sec. ... Distance= s*t = 12.5 meters

From turn-around back to hide-out:

Distance = 12.5 m. ... Time = 12.0 sec

Average speed = (total distance covered) / (time to cover the distanced)

total distance = (12.5 + 12.5) = 25 meters

total time = (2.5 + 12.0) = 14.5 sec

Average speed = (25 m) / (14.5 sec) = 1.72 m/s

Average velocity = displacement / time

The creature ended up where it started, so its displacement is zero.

Average velocity = ( 0 / 14.5 sec )

Average velocity = zero