Modern oil tankers weigh over a half-million tons and have lengths of up to one-fourth mile. such massive ships require a distance of 5.1 km (about 3.2 mi) and a time of 18 min to come to a stop from a top speed of 34 km/h. (a) what is the magnitude of such a ship's average acceleration in m/s2 in coming to a stop? (b) what is the magnitude of the ship's average velocity in m/s?

(a)

The average acceleration of the ship is given by

where

v is the final velocity

u is the initial velocity

t is the time elapsed

Here we have:

is the initial velocity

v = 0 is the final velocity

is the time elapsed

Substituting, we find

(b) 4.72 m/s

Assuming the acceleration is uniform, the average velocity of the ship is given by:

where

v is the final velocity

u is the initial velocity

Here we have:

v = 0

u = 9.44 m/s

So the average velocity of the ship is