As of 2014, science remains uncertain about what causes gravity, which is the attraction between two bodies. However, one theory is that small particles called gravitons are responsible for the force. Scientists continue... More »

Gravity causes erosion by pulling dirt, rocks and soil downward. For example, as water mixes with dirt to form soft mud, the mud cannot support itself against the force of gravity. More »

Heat, gravity, wind and running water are all causes of erosion. Each process works differently and is affected by circumstances, such as location and climate. More »

The force of gravity is an attraction that pulls all matter together. Matter is inherently attracted to other matter, due to the force of gravity. As more matter binds itself together, it exerts more gravity. More » Science Physics Motion & Mechanics

Projectile motion is caused by gravity's effect on the path of any object that is launched or thrown, according to HowStuffWorks. Projectile motion has both horizontal and vertical components. The horizontal component is... More » Science Physics Motion & Mechanics

A canal lock connects two bodies of water at different elevations by creating a water elevator of sorts. The water inside the lock can be raised and lowered independently, allowing ships to make the transition between el... More »

Friction is the resistance force that appears when two bodies or substances are rubbed together. It slows things down and opposes motion. Without friction, people would not be able to walk, run, write or play sports. Thi... More »