Motion of vehicles in water

13 Sep

Vehicles in water are moved by
a) energy from humans such as boats
b) wind energy such as sailing boats
c) energy from engine such as ships, hydrofoils and hovercrafts.


Boats are moved with oars, when water is pushed backwards by oars in a boat, a backward momentum is produced. At the same time a forward momentum of equal magnitude to the backward momentum is produced, thus moving the boat forwards.

Sailing boats and yachts

Sailing boats and yachts move using wind power by using sails.
Blowing wind is blocked by the sails which also transferred the momentum of the wind to the sails, causing the boat to move forward.


Ships use diesel engines or nuclear energy to move their propellers located at the end of the ship. Moving propellers push backwards large amounts of water thus creating a large backward momentum which also produced a forward momentum of equal magnitude and causing the ship to move forward.


A hydrofoil consists of underwater foils attached to the front and rear of its hull.

When a hydrfoil moves slowly, it behaves like any other boat. When a hydrfoil accelerates to a higher speed , the flow of water over and around the foil produces and upward force called lift or upthrust.This will raise the hydrofoil out of the water. Friction of the hull with water is reduced and the hydrofoil then can travel much faster.


A hovercraft is a vehicle that glides over a smooth surface by hovering upon an air cushion.The hovercraft creates vents of air, which are trapped beneath the vehicle by a curtain surrounding the base. These currents of air can create an air cushion on any smooth surface, land or water! Since a hovercraft can travel upon the surface of water, it is also called an amphibious vehicle.

Any object moving through water needs to overcome the drag against it. The larger the surface area that comes in contact with water, the larger the drag when the object moving through water.A streamlined-shaped object can travel through water with least water resistance or drag.


One response to “Motion of vehicles in water

  1. Born This Way Tour Australia

    25/03/2012 at 4:31 am

    An amazing article, thanks for the writing.


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