# Gravity is proportional to mass

Science tip:

All objects at the same place experience a gravitational FORCE (or pull) that is proportional to its mass. So the larger the mass, the larger the gravitational force. This force is there regardless of the speed or orientation of the object. It is there whether the object is flying or falling, whether it’s stationary or moving.

Its not in the PSLE syllabus, but students are expected to know that ALL falling objects experience the SAME gravitational ACCELERATION. Although a larger mass will have a larger gravitational force, the larger force is moving the larger mass. It works out mathematically that the acceleration is independent of its mass.

Example question: "Two balls are placed on top of a ramp.ball A has a greater mass than ball B.which ball reaches the ground first?".

Answer is both reached the ground at the same time.

Another question: "A feather and an iron ball were dropped from the same height in a vacuum. Which hit the ground first?"

Answer is both hit the ground at the same time.

Counter-intuitive? Let us know your thoughts!