barbzilla said:
I am guessing though what you would see is the car accelerating forward at high speed, then either the cable snaps (those cables don't do well under sudden force, just watch the Mythbusters Batmobile episode), the back tires lift just enough to cause the car to lose traction and slow back down (provided it is a rear wheel drive car), or it would tip the wing enough to cause the plan to tip a little encouraging the pilot to just land the plane.
Math wise what you need to look at is the load weight of that cable, the load weight of the attached areas (it looks like it claws into the plane), the weight of the car, the force generated by the speed difference between the car and the plane, the amount of lift one wing produces, the kinetic energy of the plane based on the location of the grapple point and the center of gravity, and finally the amount of force needed to lift the rear wheels off the ground causing the forward thrust to cease on the car.
i agree, thin metal cables under shock loads fail quite frequently because the strands can never be perfectly aligned and one inevitably takes most of the strain and causes a chain reaction of small shocks to snap the remaining strands one by one as they are tensioned
this is the most likely outcome, imo
but let's assume the plane dosent just snap the cable, and it tries to take off with a car attached to it's wing
it's going to be lifting the car, so the car wo'nt be producing any kind of force beyoind it's initial inertia and
it's weight on the cable
( this is why i say the clip as presented looks like nonsense,
i don't think any car could simply pull a plane from the air )
the 'merit' i see in this scene is this:
let's assume the initial inertia doesn't rip the plane from the air and just look at the weight and drag on the wing
that's what i think has a chance of downing the plane
a sensible pilot would just land, immediately if he saw a car fire a grapple onto his plane
or saw any roll on his instruments
but does he have time? how long would crashing take versus a pilot's ability to land and at what height
would that cause the plane to hit the ground unacceptably hard
if the pilot does react and attempt to land would his loss of airspeed, lift and control cause the car
to down the plane?
now, obviously i don't have, and would never try this with an actual passenger liner but i can do a simple
practical experiment to examine the forces involved and 'what they do'
i just made a paper airplane and attached paper clips to the wing, the result is the plane dives left but it is correctable by bending the wings in opposition and producing roll, this causes the plane to drift sideways slightly
but it remains aloft HOWEVER, when it slows down it falls out of the air sideways supprisingly quickly
my conclusion is it's just about the force required to overcome control surface correction
( the mass of air displaced by the rudder and ailerons )
the airspeed seems to be the critical figure here
surprisingly ( to me at-least ) the plane may stay in the air and simply ignore a car dangling off it's wing
but Only if it's travelling fast enough
madness!
still want to see what the phys guys do with it, it's a fun example.
