| English | Gravitational acceleration |
|---|---|
| Bahasa Melayu | Pecutan graviti |
| 中文 | 重力加速度 |
Definition
The acceleration of an object in free fall due to gravity, about 9.81 m s⁻² near the Earth's surface.
In exam terms
Gravitational acceleration is the acceleration of an object in free fall caused by gravity. Its symbol is g, its SI unit is the metre per second squared (m s⁻²), and near the Earth's surface it is about 9.81 m s⁻² (often taken as 10 m s⁻² in calculations).
Because it is an acceleration, it is used directly in the equations of motion. For example, an object dropped from rest gains speed at v = gt, so after 2 s its velocity is v = 10 m s⁻² × 2 s = 20 m s⁻¹ downward.
Do not confuse it with field strength
Do not confuse gravitational acceleration with gravitational field strength. They share the symbol g and have the same numerical value, but gravitational acceleration is measured in m s⁻² (an acceleration) while field strength is measured in N kg⁻¹ (force per unit mass).
Both differ from the universal gravitational constant G (6.67 × 10⁻¹¹ N m² kg⁻²).
In Paper 2 a question may ask you to state the value of the gravitational acceleration or to use g in a calculation, so quote the value with the correct unit.
Source: DSKP KSSM Physics Form 4 and 5 (Versi English) (Bahagian Pembangunan Kurikulum (BPK), KPM)