Question

An ocean liner is cruising at 10 meters/second and is about to approach a stationary ferryboat. A parcel is released from the ocean liner from a height of 5.5 meters above the ferryboat’s deck. Calculate the distance at which the ferryman should position the boat from the point horizontally below the point of release so that the parcel lands inside the boat.

Answer 1

The parcel will undergo projectile motion, which means that it will have motion in both the horizontal and vertical direction.

First, we determine how long the parcel will fall using:

s = ut + 1/2 at²

where s will be the height, u is the initial vertical velocity of the parcel (0), t is the time of fall and a is the acceleration due to gravity. 

5.5 = (0)(t) + 1/2 (9.81)(t)²
t = 1.06 seconds

Now, we may use this time to determine the horizontal distance covered by the parcel by using:
distance = velocity * time

The horizontal velocity of the parcel will be equal to the horizontal velocity of the cruise liner.

Distance = 10 * 1.06
Distance = 10.6 meters

The boat should be 10.6 meters away horizontally from the point of release.