g force in planes and cars?

Question

i understand that g force is the weight we feel on high speed, but will we feel the g force if we fly in a fighter jet in a straight line with constant speed 600 km/h. Or we feel the g force only when accelerating for example when we accelerate the plane from 200 km/h to 600 km/h for 20 seconds?

Answer 1

When you are not accelerating (you are in your chair at home, or you are in your 600mph straight line fighter jet), then you "feel" a force of 1g downward due to the pull of gravity.



Any acceleration of your jet (turns or changes in speed), will modify that feeling. The pull you feel might go up or down, or it might change direction.



If you nose over into a dive, the feeling in your chair might go to zero g, or even negative g's (where the pull is upward and blood rushes to your head). In your example where you accelerate the plane forward in a straight line, the 1g pull down changes to a "more than 1g" pull and it is directed back and down. This is identical to the force you feel in a sports car as you hit the gas.



So any acceleration of the plane modifies the force you feel.

Answer 2

"i understand that g force is the weight we feel on high speed" No it is not. G force is actually a ratio that indicates an increase or decrease in apparent weight relative to normal weight.



G force by definition is G = w/W = (W + mA)/W where W = mg is the normal weight and F = mA is additional or less force from acceleration. w is the apparent weight and g ~ M/r^2 is the gravity field.



Note, there is no "high speed" here. In fact there is no speed at all. Yet we have G force. What we need for G force is acceleration, not speed. So when that jet is flying straight and level, no matter how fast, there are no G force 'cause there's no acceleration in constant speed going straight.



EX: You are at the bottom of a loop where A = V^2/R is the centrifugal acceleration along R the loop radius. If A = g, what is the G force at the bottom of that loop. G = (mg + mg)/mg = 2 ANS. There is an increase in apparent weight here because of the acceleration generated while in the vertical turn over the radius R.

Answer 3

Only when accelerating.

Answer 4

G force is the force of GRAVITY.

The others above are discussing acceleration forces due to applying power or changes in direction.

Do not use "G" force for applying power or changes in direction, you would be shown as ignorant when using this term. One can measure applying power or changes in direction in "G's" when the unit is expressed in units of (usually Earth's) gravity. Such as " a 60 degree turn results in a 2 G acceleration."

Answer 5

The g forces created by the vehicle will only exist if the velocity changes (accelerating), this would include turns. When in motion which is "straight line with constant speed", then there is no g force from the vehicle, but you will of course still be in the Earth's gravity.

Answer 6

Force = mass x acceleration



without any kind of acceleration you will feel no g force. However if you make a turn while flying at a constant speed you will experience a force due to the angular acceleration.