1. Gravitational Field Strength
1.1. Gravitational Force
1.1.1. Varies due to the mass of place
1.1.2. Stronger on earth than moon as earth has a heavier mass
1.1.3. Pulls objects towards earth
1.1.4. Strongest at surface, weaker as it gets further away
1.2. Gravitational Field Strength g is defined as the gravitational force acting per unit mass
1.2.1. Gravitational Field is a region in which a mass experiences a force due to gravitational attraction
1.2.1.1. The gravitational force is experienced at its strongest at the surface of the Earth and gets weaker further away.
1.3. The weight of an object depends on the strength of the gravitational force acting on it.
1.4. Moon's gravitational field strength is weaker than that of Earth. Therefore, the object would weight less on Moon than on Earth. However, the mass of the object would reamin the same in both places.
2. Inertia
2.1. Refers to the reluctance of the object to change its state of rest or motion, due to its mass
2.2. Object with greater mass = Greater inertia = Greater difficulty for the object to change its state of rest or motion or speed or direction
2.3. Example:
2.3.1. Why should people wear seat belts? When there is a sudden neat to brake, the driver would continue to move forward due to his inertia
2.3.1.1. Without seat belts, the driver would crash into the windscreen
2.3.1.2. With seat belts, the driver would not crash into the windscreen
3. Weight
3.1. is the gravitational force, or gravity acting on it
3.2. If a vector quanity (Direction is towards the centre of the Earth
3.3. SI Unit: newton (N)
3.4. Weight = Mass x Gravitational Field Strength
3.5. Changes with location
3.5.1. A man has a mass of 60kg on Earth as the gravitational field strength of Earth is 10N/kg^2
3.5.2. On the moon, he would be 10kg as the gravitational field strength on the Moon is 1.6N/kg^2