Why Do Some Underwater Robots Glide by Changing Their Weight?

What Crafty Clover says in this video

Intro

Hi there, curious minds! I'm Crafty Clover! Let's discover something amazing. Why do some underwater robots glide by changing their weight?

The Big Idea

Some underwater robots glide by changing their weight, pumping oil in and out of a bladder! Making itself lighter or heavier is the whole trick. Wings then turn up-and-down motion into a slow glide forward.

Pump the Oil

Step one: pump the oil. A glider pumps oil into a flexible bladder, so it takes up more space. Taking up more space makes it float up.

Pump It Back

Step two: pump it back. When the oil goes back inside, the glider takes up less space. Then it sinks, like a stone that is heavier than the water it pushes aside.

Wings Glide

Step three: wings glide. Wings turn the up-and-down motion into a slow glide forward. It uses very little power, so it can travel for months.

A Closer Look

Let's take a closer look! A small pump moves oil around. The bladder swells or shrinks. The wings steer the glide forward. Since it does not run propellers, it saves lots of power.

Quick Facts

Quick facts! Making itself lighter or heavier is the whole trick. Gliders can collect ocean information for months at a time. Some submarines and fish control their buoyancy in similar ways. Do the bottle trick over a tray, with a grown-up helping.

Think Like a Scientist

Now, think like a scientist! With a grown-up, fill a plastic bottle with water. Drop in a small dropper with a little air in it, and put the cap on. Squeeze the bottle, and the dropper sinks! Release, and it rises.

Outro

A glider rises and sinks by changing its weight. Science is amazing! Crafty Clover can be found on Amazon Books, Google Bookstore, and Apple Books. Available for purchase or download! Bye for now!