What is the relationship between weight and g-force in determining F?

In summary, the conversation discusses the equation for g-force, with one person questioning its accuracy and the other providing a summary of how the equation is formulated. One person also brings up the concept of weight and its relation to g-force. Ultimately, it is determined that weight is considered part of the g-force, resulting in the equation F = m(g+a).
  • #1
Aqeelz
2
0
Hi.

Can you clarify for me the equation for g-force below:

F= ma + mg

I got this equation from my lecturer. He asked the class to determine how was the formula above formulated. But this is not a homework. Is the equation above true for g-force? If it's true, how does the formula come about?

I thought g-force is given by (as stated by Newton's law of universal gravitation):

F = G m1m2/r^2

I really can't see how these two equations are equal. Could you help me out? Thanks!
 
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  • #2
Now that I have had a good look at my question, I thought about the following:

F = ma + mg
F - mg = ma
F - Fg = ma
→ ƩFnet = F - Fg = ma

Actually I will be on a trip to ride a roller coaster. Our class was asked to determine first how was the 'formula for g-force' F = ma + mg formulated.

If an object falls freely downward, it would be subjected to g (acceleration due to gravity). Time this with the object' mass we would obtain its weight/ gravitational force, Fg. However Newton's 3rd law states that for every action there is an equal but opposite reaction, hence this opposite force, denoted as F, which is directed upward (opposite Fg), but has an equal magnitude to that of Fg. The net force, ƩFnet, is then the difference between these two forces (F and Fg) and it must obey Newton's 2nd law, which is
ƩFnet = ma​

Therefore, the F in the equation F = ma + mg (given by my lecturer) is not really a g-force, is it? Because g-force is already given by Fg = mg. In other words, F = ma + mg is not an equation to find the gravitational force, right?

Am I right? If not, please correct me.

Thanks!
 
Last edited:
  • #3
Well, mg is the force due to gravity alone - which we call 'weight'.

Is weight a g-force, or do we consider the other 'peculiar' forces (a) experienced on a ride the 'g-force' and leave weight out of it? Or is it all g-force?

It's just semantics, but generally we'd consider weight part of the g-force so it's g+a.
So F = m(g+a)
 

Related to What is the relationship between weight and g-force in determining F?

1) What is the G-force equation?

The G-force equation is a mathematical formula used to calculate the amount of force experienced by an object due to acceleration. It is often used in physics and aerospace engineering to determine the effects of rapid acceleration on humans and objects.

2) How is the G-force equation calculated?

The G-force equation is calculated by multiplying an object's mass by its acceleration. It can be expressed as G = ma, where G is the G-force, m is the mass of the object, and a is the acceleration.

3) What units are used in the G-force equation?

The units used in the G-force equation depend on the specific units used for mass and acceleration. However, commonly used units for G-force include "g" (for gravitational force) and "m/s²" (for acceleration). It is important to ensure that the units are consistent throughout the equation.

4) What is the significance of G-force in space travel?

G-force is a crucial factor in space travel because it can greatly impact the health and safety of astronauts. High G-forces can cause physical discomfort, loss of consciousness, and even permanent injury. Therefore, understanding and controlling G-forces is essential for successful space missions.

5) How can I use the G-force equation in real-life applications?

The G-force equation can be used in various real-life applications, such as designing roller coasters, calculating the effects of car crashes, and understanding the forces experienced by pilots during flight. It is also used in sports science to measure the forces athletes experience during intense physical activities.

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