In the early part of the 1900’s, automakers were still experimenting with fuel sources – and the basic laws of physics. The pic to the right is a riddle from a 1932 edition of Modern Mechanix magazine where they asked readers to figure out which vehicle would be propelled forward to send in their answer. $10 would be handed out to a random correct entry. $10! Gee whiz, mister. Spanks a bundle. So yeah, which truck would move forward, genius?
Modern Mechanix via MAKE
The second one will, unless the first has a secret Tesla engine!
The second one is not going to move, theoretically the first one could, depending on the bearings… :)
The water and the balls will have the same affect, untill the balls run out.
They will both do nothing but stand still.
For the first car, the balls wil just roll off to the one ‘driving’ behind you. (there is no opposite force, and even if the balls wóuld magically drop into a concrete wall there wouldn’t be enough force (gravity) to propell a vehicle)
For the second car: this will also absolutely do nothing. Same reason, there’s nothing to with enough force to propell the car. Sure, it will make a nice splash though, but i think it’ll run out of water soon :P
the fist one will move and the second one will not
Since the lead balls have energy while leaving the system, technically they should impart an opposite force upon the vehicle. Then the question becomes whether that force is enough to overcome the inertia of the truck to get it to move. The problem designers don’t say to ignore inertia, so I must assume it is present, and the first truck won’t move.
The water truck shouldn’t move, since it is a closed system. All force is maintained within the system, not transferred outside, so no “equal and opposite reaction” to be had to propel the vehicle forward.
Sorry in advance for the double post.
I think the balls one would run, since the force imparted on them by gravity would be expended once they hit the ramp, which if the truck has very little inertia and friction, could drive it forward somewhat.
Well scratch that, neither of them will move. I thought the water being collected in the second was actually being used to move the wheels!
The first one. Due to the potential energy being converted into kinetic energy as they hit the flank at the end of the car, the car might move forward just a bit. So, the first one
Whichever one is facing down a hill. Or, whichever is being pulled in ESPN’s “World’s Strongest Man” competition.
Obviously.
The first one, but only with no driver and once most of the lead balls are gone. With the additional weight the force of the balls would not move the vehicle. This also depends on the weight of the cab and the bearings in the wheels.