Lesson 1: Gravitational Forces

Definition:

  • Gravitational forces are an invisible force of gravity that pulls all objects with masses together.

Deeper Understanding:

Gravitational Force Depends on These 2 Factors:

  1. Mass: The more matter an object has, the stronger its gravitational pull. For example, Earth is bigger than the Moon, so Earth has a stronger gravitational force.

  2. Distance: The closer two objects are from each other, the stronger the gravitational force. This is why in space, there is a weaker gravitational pull and it feels weightless- because astronauts are always orbiting Earth and their distance from Earth reduces the gravitational pull. They are also in a freefall situation.

Example of Khan Academy:

Fill in the blanks:

The gravitational pull between Planet A and B are stronger when they have a ____ mass and they are _____.

Blank 1 Choose From: Heavier, Lighter

Blank 2 Choose From: Farther Away, Closer Together

Key Points:

  • Two objects can never have a zero gravitational force because as long as each of them have a mass, they will exert some gravitational pull on each other.

  • The heavier the two objects, the stronger the gravitational force. Vice versa, the lighter the objects, the weaker the pull.

  • Distance also matters! If two objects are close together, the gravitational force is stronger than two objects stretched far away from each other.