G Force Calculator

This g force calculator helps determine the acceleration experienced by a moving object in terms of the Earth’s gravitational acceleration. The tool first establishes the acceleration due to gravity and then computes the gravitational force equivalent based on the moving speed of any entity.

Read on to understand how you can calculate the g force from the velocity of an object.

The g force or g-force, otherwise known as the gravitational force equivalent, is the force per unit mass experienced by an object with reference to the acceleration to due to gravity value — $9.81 \text{ m/s}^2$ or $32.17\text{ ft/s}^2$. The force experienced by an object resting on the earth's surface is roughly $1 g$. Note the $g$ is different from the unit of weight grams ($\text{g}$).

The g force is directly proportional to the object's acceleration, such that a pilot experiences as much as $8 g$ and $-5 g$. When the g value is positive, the pilot's blood rushes towards his feet, leading to blackouts or losing consciousness.

A negative g value causes blood flow towards the brain and eyes, resulting in swelling veins and reddened visions. We can also experience the same rush on roller coaster rides, during which people often lose consciousness.

Mathematically, the acceleration due to gravity, $g$, for an object is:

where:

• $G$ – Universal gravitational constant, $6.674 \times 10^{-11} \text{ m}^{3} \text{kg}^{-1} \text{s}^{-2}$;
• $M$ – Mass of the celestial body (e.g., planet Earth); and
• $r$ – Radius of celestial body.

If you know the acceleration due to gravity value, you can further calculate the g force from velocity. Suppose an object has an initial velocity $v_0$ and final velocity $v_1$ over a time interval, $t$. The equation gives the g force:

It is interesting to notice that the term $\large \frac {v_1 - v_0}{t}$ is acceleration of an object.

Estimate the g force on a person suddenly stopping his car in $1 \text{ s}$ that was traveling at a velocity of $60 \text{ km/h}$.

To calculate the g force:

1. Enter the initial velocity, $v_0 = 60 \text{ km/h}$ or $16.67 \text{ m/s}$.

2. Fill in the final velocity, $v_1 = 0 \text{ km/h}$.

3. Set the time, $t = 1\text{ s}$.

4. The calculator returns the g value using the equation:

The driver experiences a negative g force value of $-1.697 \ g$ when he suddenly stops his car.

You can explore the similar calculators listed below if you like this one:

• Gravitational force calculator; and
• Acceleration due to gravity calculator.