Why do most Raptors lean right when jumping?

[Jakenbake]

While the feather and anvil accelerate towards the ground at the same 9.8 m/s/s, (neglecting air resistance, only in a vacuum), they only hit the ground at the same time if initial displacement from the ground is equal. So could the passenger side of the truck be slightly heavier, therefore never reaching the same vertical displacement as the drivers side, thus travelling a shorter distance to the ground than the passenger side as well as some of the axis of rotation being in effect?

~50lb Battery - Passenger
~275lbs Fuel tank and fuel - driver
???Transfer case - driver-ish
???Bulk of exhaust - passenger
~200lbs Driver - driver
????Passenger (if applicable) - passenger

Distance from centerline of vehicle also has an effect on the moment created by the off center item. This should be a decent start. Feel free to modify the list if you want.

I wouldnt be shocked if there isn’t data on the C.O.G. For a F150 somewhere on the internet already though.

 

[BSheppard]

I always thought it was rotation mass twisting the truck that direction. You have a lot of spinning mass with the engine, crank, drive shaft, etc. That in my mind would have the passenger side a little lower.

9.81M per sec down all being the same on the driver as the passenger.

 

[Venerous]

I'm not sure I agree with this, particularly about the truck lifting. Perhaps I don't follow what you mean, but 'lift' would imply that the truck is lifting off the ground like an airplane achieves lift with it's wings. I don't think that's really happening with a truck, and I don't think the right side, the lighter side, is leaving the ground sooner than the left side.

My guess, and it is just a guess, is that the left side is applying more force against gravity, and therefore, stays in the air longer as it has more force to overcome gravity. Force is mass* acceleration, right? If both sides of the truck have equal acceleration, but the left side has more mass, then the left side has more force. And since gravity is the same force on objects regardless of their mass, then force of gravity would mean that the right side would not travel as high on the left side (since less force is applied against gravity than the right) ... and therefore, the left side would land sooner.

I wouldn't be surprised if that's totally incorrect though. My brain tells me that if two separate vehicles with different weights approach the same jump with the same acceleration, the lighter vehicle would go higher and land later. But, this is one of those things where your instinct isn't always right. I think the reality is that the lighter vehicle is likely to approach the jump with greater acceleration, and thus apply the same or more force than the heavier vehicle would. All I know for sure is that a heavier object doesn't fall faster than a lighter object, so the reason one side falls sooner than the other has to be on the rising part of the jump, rather than the falling.

@melvimbe - I was merely using the term "lift" to describe the process of the wheel(s) terminating their contact with the earth - I did not mean to give the impression that I was using it in the aviation sense.

That said, I perhaps too crudely explained my point. Your second paragraph provided more detail about what I was trying to convey however, this equation is more than just the convergence of mass, speed, and gravity. I don't have all the specific data (exact numbers and whatnot) and I could very well be wrong but in addition to those, you also have the shocks and springs compressing and decompressing which would add to the roll (rotation along the Z axis) of the vehicle. Even if by a nanosecond, the driver side would leave the ground later as @GordoJay more thoroughly explained in his second post of this thread.

My apologies for not better explaining myself in my first post. I was just trying to answer the question while saving readers the physics lesson. So, @Jakenbake - yes: any deviation from the wheels being at 0 degrees relative and the lay of the land all play a larger roll but, all assuming all of those factors had a negligible influence - 200 or so pounds could make enough difference.

Now that I've nerded out though, let me propose a different theory - could people being predominantly right handed play any part in this? EX: How they grip the wheel, drop their arm, etc. as the launch.

 

[GordoJay]

Now that I've nerded out though, let me propose a different theory - could people being predominantly right handed play any part in this? EX: How they grip the wheel, drop their arm, etc. as the launch.

It could be that because the driver is off the center line, what looks like hitting a jump squarely isn't. My wife has this problem with lines in parking lots.

 

[sixshooter_45]

Thanks, now my head hurts and I like math.

LOL!

 

[melvimbe]

The mistake you appear to be making is to think of gravity as a force, rather than as an acceleration. Gravity produces the force in conjunction with the mass of the object that it interacts with, but it isn't a force.

Well gravity is a force, but you are correct that it's logical to just think of it as an acceleration constant. The mass of the earth is constant, the force is constant, and therefore, so is the acceleration...basically.

Objects don't apply a force against gravity, it's gravity that applies force on objects. Objects apply force against the ground because gravity is pulling them down into the ground but they don't resist gravity, what they resist is being pulled through another solid object, the ground. The force that gravity produces is linearly related to the mass of the object, using F=ma, where a is equal to g, the acceleration of gravity, which is a constant at the Earth's surface. The reason that heavy objects and light objects fall at the same speed, neglecting air resistance, is that g=F/m. Since g is constant, F and m scale linearly. More force is applied to larger masses and thus all objects fall(accelerate downward) at the same speed.

I think this help me figured out where I was wrong. Whether I said it correctly or not, I had gravity correct, but I was looking at the opposing truck as a force, which is incorrect once it's airborne. Once airborne, the wheels aren't pushing against anything and applying any force, what you have at that point is momentum, or mass * velocity. Since, both sides have the same velocity, but the left side has more mass, the left side has more momentum. Thus, the force of gravity would need to be applied longer to stop the momentum of the left side, and therefore, the left side should reach a higher altitude and take longer to return back to earth....I think.

As an example if a bicycle and a semi are traveling at the same speed, apply brakes with the same force (same gravity is the same force) to both 'vehicles' would result in the bicycle coming to stop much sooner than the semi. Or, I would rather be hit by a bicycle at 20 mph that an semi at the same (or lesser speed).

As a different example if you were able to launch a 10 lb rock in the air at the same velocity as a 5 lb rock, the 10 lb rock should stay in the air longer (more momentum). If you launched the rocks in the air with the same amount of force, then they should have the same momentum and thus hit the ground at the same time....I think.

If this is correct though, this would mean that if a Raptor and TRX take the same jump at the same speed, the TRX should get a little higher and travel farther...since it has more mass and thus more momentum.

Although, I do think with the truck, there is a turning effect as others have stated. Not sure how much the difference in mass of the truck matters.

All the said, I may still be wrong, or the difference in mass from left to right may not be different. I would guess that this is a factor.

 

[Jakenbake]

Well gravity is a force, but you are correct that it's logical to just think of it as an acceleration constant. The mass of the earth is constant, the force is constant, and therefore, so is the acceleration...basically.



I think this help me figured out where I was wrong. Whether I said it correctly or not, I had gravity correct, but I was looking at the opposing truck as a force, which is incorrect once it's airborne. Once airborne, the wheels aren't pushing against anything and applying any force, what you have at that point is momentum, or mass * velocity. Since, both sides have the same velocity, but the left side has more mass, the left side has more momentum. Thus, the force of gravity would need to be applied longer to stop the momentum of the left side, and therefore, the left side should reach a higher altitude and take longer to return back to earth....I think.

As an example if a bicycle and a semi are traveling at the same speed, apply brakes with the same force (same gravity is the same force) to both 'vehicles' would result in the bicycle coming to stop much sooner than the semi. Or, I would rather be hit by a bicycle at 20 mph that an semi at the same (or lesser speed).

As a different example if you were able to launch a 10 lb rock in the air at the same velocity as a 5 lb rock, the 10 lb rock should stay in the air longer (more momentum). If you launched the rocks in the air with the same amount of force, then they should have the same momentum and thus hit the ground at the same time....I think.

If this is correct though, this would mean that if a Raptor and TRX take the same jump at the same speed, the TRX should get a little higher and travel farther...since it has more mass and thus more momentum.

Although, I do think with the truck, there is a turning effect as others have stated. Not sure how much the difference in mass of the truck matters.

All the said, I may still be wrong, or the difference in mass from left to right may not be different. I would guess that this is a factor.

In your example about the 10lb rock and the 5lb rock. If they have the same initial velocity and the same angle from the horizontal then they would go the same horizontal distance. Projectile motion equations, they would have the same vertical and horizontal components.

 

[SkyPilot]

Well. I always thought it was the sum of all the gyroscopic forces generated by all the rotating mass. Talk to anyone that has flown an airplane with a propeller and they will tell you all about using the rudder to compensate for the rolling tendency as the power is advanced or retarded. A P-51 Mustang World War 2 fighter pilot at slow airspeeds with the resulting reduced rudder effectiveness could not just mindlessly slam the throttle to the firewall with out experiencing "torque roll" that could often be severe enough to lose control of the airplane.

 

[GCATX]

Well. I always thought it was the sum of all the gyroscopic forces generated by all the rotating mass. Talk to anyone that has flown an airplane with a propeller and they will tell you all about using the rudder to compensate for the rolling tendency as the power is advanced or retarded. A P-51 Mustang World War 2 fighter pilot at slow airspeeds with the resulting reduced rudder effectiveness could not just mindlessly slam the throttle to the firewall with out experiencing "torque roll" that could often be severe enough to lose control of the airplane.

Agreed. Go out to your truck, open the hood and have someone blip the gas pedal. The motor will rotate up on the driver side. Easiest way to check for a blown motor mount too.

 

[GordoJay]

I think this help me figured out where I was wrong. Whether I said it correctly or not, I had gravity correct, but I was looking at the opposing truck as a force, which is incorrect once it's airborne. Once airborne, the wheels aren't pushing against anything and applying any force, what you have at that point is momentum, or mass * velocity. Since, both sides have the same velocity, but the left side has more mass, the left side has more momentum. Thus, the force of gravity would need to be applied longer to stop the momentum of the left side, and therefore, the left side should reach a higher altitude and take longer to return back to earth....I think.

No. A rigid body is one piece, one part of it can't have more momentum than another part unless the parts separate. Whatever is causing the rotation isn't gravity acting once the truck is airborne.

As an example if a bicycle and a semi are traveling at the same speed, apply brakes with the same force (same gravity is the same force) to both 'vehicles' would result in the bicycle coming to stop much sooner than the semi.

No, they will stop at the same time in the same distance, just as they would fall at the same speed if you threw them off a bridge.

Or, I would rather be hit by a bicycle at 20 mph that an semi at the same (or lesser speed).

True, but irrelevant. Momentum and acceleration are completely different things. You can't swap one for the other.

As a different example if you were able to launch a 10 lb rock in the air at the same velocity as a 5 lb rock, the 10 lb rock should stay in the air longer (more momentum). If you launched the rocks in the air with the same amount of force, then they should have the same momentum and thus hit the ground at the same time....I think.

You're mixing up force and velocity. If you launch them at the same velocity, they land at the same time. Depending on how long you apply the force to the different masses, the velocities may differ. The one with the higher velocity will have the longest hang time.

If this is correct though, this would mean that if a Raptor and TRX take the same jump at the same speed, the TRX should get a little higher and travel farther...since it has more mass and thus more momentum.

If it was correct, that would be true. But it's not. Same speed, same distance, same height, assuming that the suspensions act the same. A bicycle, a pickup, and a semi will all get the same distance off the ground so long as the spring rate of the suspension is proportional to the mass. You wouldn't expect the bicycle to get a quarter inch, the pickup four feet, and the semi 55 feet in the air when they all hit the same jump at the same speed. If the bicycle weighs 30lb, the pickup 6,000lb, and the semi 80,000lb, that's what you would get. I'm pretty sure that doesn't happen.

All the said, I may still be wrong, or the difference in mass from left to right may not be different. I would guess that this is a factor.

The only way I can see the difference in mass from side to side making a difference is if the springs are progressive. Maybe. I'll have to think about that for a bit. It may or may not make a difference and it's complicated enough that the answer isn't obvious in my post happy hour condition.